From 4a19edb60d0203cd5bf95a8b46ea8f63fd41194c Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:22 -0700 Subject: [PATCH 01/23] netlink: Pass extack to dump handlers Declare extack in netlink_dump and pass to dump handlers via netlink_callback. Add any extack message after the dump_done_errno allowing error messages to be returned. This will be useful when strict checking is done on dump requests, returning why the dump fails EINVAL. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- include/linux/netlink.h | 1 + net/netlink/af_netlink.c | 12 +++++++++++- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/include/linux/netlink.h b/include/linux/netlink.h index 71f121b66ca8..88c8a2d83eb3 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -176,6 +176,7 @@ struct netlink_callback { void *data; /* the module that dump function belong to */ struct module *module; + struct netlink_ext_ack *extack; u16 family; u16 min_dump_alloc; unsigned int prev_seq, seq; diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index e3a0538ec0be..7ac585f33a9e 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2171,6 +2171,7 @@ EXPORT_SYMBOL(__nlmsg_put); static int netlink_dump(struct sock *sk) { struct netlink_sock *nlk = nlk_sk(sk); + struct netlink_ext_ack extack = {}; struct netlink_callback *cb; struct sk_buff *skb = NULL; struct nlmsghdr *nlh; @@ -2222,8 +2223,11 @@ static int netlink_dump(struct sock *sk) skb_reserve(skb, skb_tailroom(skb) - alloc_size); netlink_skb_set_owner_r(skb, sk); - if (nlk->dump_done_errno > 0) + if (nlk->dump_done_errno > 0) { + cb->extack = &extack; nlk->dump_done_errno = cb->dump(skb, cb); + cb->extack = NULL; + } if (nlk->dump_done_errno > 0 || skb_tailroom(skb) < nlmsg_total_size(sizeof(nlk->dump_done_errno))) { @@ -2246,6 +2250,12 @@ static int netlink_dump(struct sock *sk) memcpy(nlmsg_data(nlh), &nlk->dump_done_errno, sizeof(nlk->dump_done_errno)); + if (extack._msg && nlk->flags & NETLINK_F_EXT_ACK) { + nlh->nlmsg_flags |= NLM_F_ACK_TLVS; + if (!nla_put_string(skb, NLMSGERR_ATTR_MSG, extack._msg)) + nlmsg_end(skb, nlh); + } + if (sk_filter(sk, skb)) kfree_skb(skb); else From 3d0d4337d7a105c5e8ba85c6e7b75437b4c6745e Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:23 -0700 Subject: [PATCH 02/23] netlink: Add extack message to nlmsg_parse for invalid header length Give a user a reason why EINVAL is returned in nlmsg_parse. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- include/net/netlink.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/include/net/netlink.h b/include/net/netlink.h index 589683091f16..9522a0bf1f3a 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -516,8 +516,10 @@ static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, const struct nla_policy *policy, struct netlink_ext_ack *extack) { - if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) + if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) { + NL_SET_ERR_MSG(extack, "Invalid header length"); return -EINVAL; + } return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), nlmsg_attrlen(nlh, hdrlen), policy, extack); From dac9c9790e542777079999900594fd069ba10489 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:24 -0700 Subject: [PATCH 03/23] net: Add extack to nlmsg_parse Make sure extack is passed to nlmsg_parse where easy to do so. Most of these are dump handlers and leveraging the extack in the netlink_callback. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- net/core/devlink.c | 2 +- net/core/neighbour.c | 3 ++- net/core/rtnetlink.c | 4 ++-- net/ipv4/devinet.c | 9 +++++---- net/ipv6/addrconf.c | 2 +- net/ipv6/route.c | 2 +- net/mpls/af_mpls.c | 2 +- net/netfilter/ipvs/ip_vs_ctl.c | 2 +- net/sched/act_api.c | 2 +- net/sched/cls_api.c | 6 ++++-- net/sched/sch_api.c | 2 +- net/xfrm/xfrm_user.c | 2 +- 12 files changed, 21 insertions(+), 17 deletions(-) diff --git a/net/core/devlink.c b/net/core/devlink.c index 938f68ee92f0..6dae81d65d5c 100644 --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -3504,7 +3504,7 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb, start_offset = *((u64 *)&cb->args[0]); err = nlmsg_parse(cb->nlh, GENL_HDRLEN + devlink_nl_family.hdrsize, - attrs, DEVLINK_ATTR_MAX, ops->policy, NULL); + attrs, DEVLINK_ATTR_MAX, ops->policy, cb->extack); if (err) goto out; diff --git a/net/core/neighbour.c b/net/core/neighbour.c index fb023df48b83..b06f794bf91e 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -2445,7 +2445,8 @@ static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb) ((struct ndmsg *)nlmsg_data(nlh))->ndm_flags == NTF_PROXY) proxy = 1; - err = nlmsg_parse(nlh, sizeof(struct ndmsg), tb, NDA_MAX, NULL, NULL); + err = nlmsg_parse(nlh, sizeof(struct ndmsg), tb, NDA_MAX, NULL, + cb->extack); if (!err) { if (tb[NDA_IFINDEX]) { if (nla_len(tb[NDA_IFINDEX]) != sizeof(u32)) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 5564eee1e980..4486e8b7d9d0 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1909,7 +1909,7 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) sizeof(struct rtgenmsg) : sizeof(struct ifinfomsg); if (nlmsg_parse(cb->nlh, hdrlen, tb, IFLA_MAX, - ifla_policy, NULL) >= 0) { + ifla_policy, cb->extack) >= 0) { if (tb[IFLA_TARGET_NETNSID]) { netnsid = nla_get_s32(tb[IFLA_TARGET_NETNSID]); tgt_net = rtnl_get_net_ns_capable(skb->sk, netnsid); @@ -3774,7 +3774,7 @@ static int rtnl_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb) (nlmsg_len(cb->nlh) != sizeof(struct ndmsg) + nla_attr_size(sizeof(u32)))) { err = nlmsg_parse(cb->nlh, sizeof(struct ifinfomsg), tb, - IFLA_MAX, ifla_policy, NULL); + IFLA_MAX, ifla_policy, cb->extack); if (err < 0) { return -EINVAL; } else if (err == 0) { diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index 44d931a3cd50..ab2b11df5ea4 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -782,7 +782,8 @@ static void set_ifa_lifetime(struct in_ifaddr *ifa, __u32 valid_lft, } static struct in_ifaddr *rtm_to_ifaddr(struct net *net, struct nlmsghdr *nlh, - __u32 *pvalid_lft, __u32 *pprefered_lft) + __u32 *pvalid_lft, __u32 *pprefered_lft, + struct netlink_ext_ack *extack) { struct nlattr *tb[IFA_MAX+1]; struct in_ifaddr *ifa; @@ -792,7 +793,7 @@ static struct in_ifaddr *rtm_to_ifaddr(struct net *net, struct nlmsghdr *nlh, int err; err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv4_policy, - NULL); + extack); if (err < 0) goto errout; @@ -897,7 +898,7 @@ static int inet_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, ASSERT_RTNL(); - ifa = rtm_to_ifaddr(net, nlh, &valid_lft, &prefered_lft); + ifa = rtm_to_ifaddr(net, nlh, &valid_lft, &prefered_lft, extack); if (IS_ERR(ifa)) return PTR_ERR(ifa); @@ -1684,7 +1685,7 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb) s_ip_idx = ip_idx = cb->args[2]; if (nlmsg_parse(cb->nlh, sizeof(struct ifaddrmsg), tb, IFA_MAX, - ifa_ipv4_policy, NULL) >= 0) { + ifa_ipv4_policy, cb->extack) >= 0) { if (tb[IFA_TARGET_NETNSID]) { fillargs.netnsid = nla_get_s32(tb[IFA_TARGET_NETNSID]); diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index a9a317322388..2f8aa4fd5e55 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -5021,7 +5021,7 @@ static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, s_ip_idx = ip_idx = cb->args[2]; if (nlmsg_parse(cb->nlh, sizeof(struct ifaddrmsg), tb, IFA_MAX, - ifa_ipv6_policy, NULL) >= 0) { + ifa_ipv6_policy, cb->extack) >= 0) { if (tb[IFA_TARGET_NETNSID]) { netnsid = nla_get_s32(tb[IFA_TARGET_NETNSID]); diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 74d97addf1af..7c38e0e058ae 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -4117,7 +4117,7 @@ static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh, int err; err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy, - NULL); + extack); if (err < 0) goto errout; diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c index 8fbe6cdbe255..55a30ee3d820 100644 --- a/net/mpls/af_mpls.c +++ b/net/mpls/af_mpls.c @@ -1223,7 +1223,7 @@ static int mpls_netconf_get_devconf(struct sk_buff *in_skb, int err; err = nlmsg_parse(nlh, sizeof(*ncm), tb, NETCONFA_MAX, - devconf_mpls_policy, NULL); + devconf_mpls_policy, extack); if (err < 0) goto errout; diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index 62eefea48973..83395bf6dc35 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -3234,7 +3234,7 @@ static int ip_vs_genl_dump_dests(struct sk_buff *skb, /* Try to find the service for which to dump destinations */ if (nlmsg_parse(cb->nlh, GENL_HDRLEN, attrs, IPVS_CMD_ATTR_MAX, - ip_vs_cmd_policy, NULL)) + ip_vs_cmd_policy, cb->extack)) goto out_err; diff --git a/net/sched/act_api.c b/net/sched/act_api.c index 55153da00278..9c1b0729aebf 100644 --- a/net/sched/act_api.c +++ b/net/sched/act_api.c @@ -1452,7 +1452,7 @@ static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb) u32 act_count = 0; ret = nlmsg_parse(cb->nlh, sizeof(struct tcamsg), tb, TCA_ROOT_MAX, - tcaa_policy, NULL); + tcaa_policy, cb->extack); if (ret < 0) return ret; diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index d670d3066ebd..43c8559aca56 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -1727,7 +1727,8 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) if (nlmsg_len(cb->nlh) < sizeof(*tcm)) return skb->len; - err = nlmsg_parse(cb->nlh, sizeof(*tcm), tca, TCA_MAX, NULL, NULL); + err = nlmsg_parse(cb->nlh, sizeof(*tcm), tca, TCA_MAX, NULL, + cb->extack); if (err) return err; @@ -2054,7 +2055,8 @@ static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb) if (nlmsg_len(cb->nlh) < sizeof(*tcm)) return skb->len; - err = nlmsg_parse(cb->nlh, sizeof(*tcm), tca, TCA_MAX, NULL, NULL); + err = nlmsg_parse(cb->nlh, sizeof(*tcm), tca, TCA_MAX, NULL, + cb->extack); if (err) return err; diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index da1963b19dec..cf5c714ae786 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -1671,7 +1671,7 @@ static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb) ASSERT_RTNL(); err = nlmsg_parse(nlh, sizeof(struct tcmsg), tca, TCA_MAX, - rtm_tca_policy, NULL); + rtm_tca_policy, cb->extack); if (err < 0) return err; diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index df7ca2dabc48..ca7a207b81a9 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -1007,7 +1007,7 @@ static int xfrm_dump_sa(struct sk_buff *skb, struct netlink_callback *cb) int err; err = nlmsg_parse(cb->nlh, 0, attrs, XFRMA_MAX, xfrma_policy, - NULL); + cb->extack); if (err < 0) return err; From a5f6cba291654168e6ab73c3e7ff5b27371c4cb9 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:25 -0700 Subject: [PATCH 04/23] netlink: Add strict version of nlmsg_parse and nla_parse nla_parse is currently lenient on message parsing, allowing type to be 0 or greater than max expected and only logging a message "netlink: %d bytes leftover after parsing attributes in process `%s'." if the netlink message has unknown data at the end after parsing. What this could mean is that the header at the front of the attributes is actually wrong and the parsing is shifted from what is expected. Add a new strict version that actually fails with EINVAL if there are any bytes remaining after the parsing loop completes, if the atttrbitue type is 0 or greater than max expected. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- include/net/netlink.h | 17 +++++++++++++++ lib/nlattr.c | 50 ++++++++++++++++++++++++++++++++----------- 2 files changed, 54 insertions(+), 13 deletions(-) diff --git a/include/net/netlink.h b/include/net/netlink.h index 9522a0bf1f3a..f1db8e594847 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -373,6 +373,9 @@ int nla_validate(const struct nlattr *head, int len, int maxtype, int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, int len, const struct nla_policy *policy, struct netlink_ext_ack *extack); +int nla_parse_strict(struct nlattr **tb, int maxtype, const struct nlattr *head, + int len, const struct nla_policy *policy, + struct netlink_ext_ack *extack); int nla_policy_len(const struct nla_policy *, int); struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype); size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize); @@ -525,6 +528,20 @@ static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, nlmsg_attrlen(nlh, hdrlen), policy, extack); } +static inline int nlmsg_parse_strict(const struct nlmsghdr *nlh, int hdrlen, + struct nlattr *tb[], int maxtype, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) { + NL_SET_ERR_MSG(extack, "Invalid header length"); + return -EINVAL; + } + + return nla_parse_strict(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), + nlmsg_attrlen(nlh, hdrlen), policy, extack); +} + /** * nlmsg_find_attr - find a specific attribute in a netlink message * @nlh: netlink message header diff --git a/lib/nlattr.c b/lib/nlattr.c index 1e900bb414ef..d26de6156b97 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -391,9 +391,10 @@ EXPORT_SYMBOL(nla_policy_len); * * Returns 0 on success or a negative error code. */ -int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, - int len, const struct nla_policy *policy, - struct netlink_ext_ack *extack) +static int __nla_parse(struct nlattr **tb, int maxtype, + const struct nlattr *head, int len, + bool strict, const struct nla_policy *policy, + struct netlink_ext_ack *extack) { const struct nlattr *nla; int rem; @@ -403,27 +404,50 @@ int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, nla_for_each_attr(nla, head, len, rem) { u16 type = nla_type(nla); - if (type > 0 && type <= maxtype) { - if (policy) { - int err = validate_nla(nla, maxtype, policy, - extack); - - if (err < 0) - return err; + if (type == 0 || type > maxtype) { + if (strict) { + NL_SET_ERR_MSG(extack, "Unknown attribute type"); + return -EINVAL; } - - tb[type] = (struct nlattr *)nla; + continue; } + if (policy) { + int err = validate_nla(nla, maxtype, policy, extack); + + if (err < 0) + return err; + } + + tb[type] = (struct nlattr *)nla; } - if (unlikely(rem > 0)) + if (unlikely(rem > 0)) { pr_warn_ratelimited("netlink: %d bytes leftover after parsing attributes in process `%s'.\n", rem, current->comm); + NL_SET_ERR_MSG(extack, "bytes leftover after parsing attributes"); + if (strict) + return -EINVAL; + } return 0; } + +int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, + int len, const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + return __nla_parse(tb, maxtype, head, len, false, policy, extack); +} EXPORT_SYMBOL(nla_parse); +int nla_parse_strict(struct nlattr **tb, int maxtype, const struct nlattr *head, + int len, const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + return __nla_parse(tb, maxtype, head, len, true, policy, extack); +} +EXPORT_SYMBOL(nla_parse_strict); + /** * nla_find - Find a specific attribute in a stream of attributes * @head: head of attribute stream From 6ba1e6e856ab0531c5e0a5ecefc9fff8490d9a04 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:26 -0700 Subject: [PATCH 05/23] net/ipv6: Refactor address dump to push inet6_fill_args to in6_dump_addrs Pull the inet6_fill_args arg up to in6_dump_addrs and move netnsid into it. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 57 ++++++++++++++++++++++++--------------------- 1 file changed, 30 insertions(+), 27 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 2f8aa4fd5e55..afa279170ba5 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -4793,12 +4793,19 @@ static inline int inet6_ifaddr_msgsize(void) + nla_total_size(4) /* IFA_RT_PRIORITY */; } +enum addr_type_t { + UNICAST_ADDR, + MULTICAST_ADDR, + ANYCAST_ADDR, +}; + struct inet6_fill_args { u32 portid; u32 seq; int event; unsigned int flags; int netnsid; + enum addr_type_t type; }; static int inet6_fill_ifaddr(struct sk_buff *skb, struct inet6_ifaddr *ifa, @@ -4930,39 +4937,28 @@ static int inet6_fill_ifacaddr(struct sk_buff *skb, struct ifacaddr6 *ifaca, return 0; } -enum addr_type_t { - UNICAST_ADDR, - MULTICAST_ADDR, - ANYCAST_ADDR, -}; - /* called with rcu_read_lock() */ static int in6_dump_addrs(struct inet6_dev *idev, struct sk_buff *skb, - struct netlink_callback *cb, enum addr_type_t type, - int s_ip_idx, int *p_ip_idx, int netnsid) + struct netlink_callback *cb, + int s_ip_idx, int *p_ip_idx, + struct inet6_fill_args *fillargs) { - struct inet6_fill_args fillargs = { - .portid = NETLINK_CB(cb->skb).portid, - .seq = cb->nlh->nlmsg_seq, - .flags = NLM_F_MULTI, - .netnsid = netnsid, - }; struct ifmcaddr6 *ifmca; struct ifacaddr6 *ifaca; int err = 1; int ip_idx = *p_ip_idx; read_lock_bh(&idev->lock); - switch (type) { + switch (fillargs->type) { case UNICAST_ADDR: { struct inet6_ifaddr *ifa; - fillargs.event = RTM_NEWADDR; + fillargs->event = RTM_NEWADDR; /* unicast address incl. temp addr */ list_for_each_entry(ifa, &idev->addr_list, if_list) { if (++ip_idx < s_ip_idx) continue; - err = inet6_fill_ifaddr(skb, ifa, &fillargs); + err = inet6_fill_ifaddr(skb, ifa, fillargs); if (err < 0) break; nl_dump_check_consistent(cb, nlmsg_hdr(skb)); @@ -4970,26 +4966,26 @@ static int in6_dump_addrs(struct inet6_dev *idev, struct sk_buff *skb, break; } case MULTICAST_ADDR: - fillargs.event = RTM_GETMULTICAST; + fillargs->event = RTM_GETMULTICAST; /* multicast address */ for (ifmca = idev->mc_list; ifmca; ifmca = ifmca->next, ip_idx++) { if (ip_idx < s_ip_idx) continue; - err = inet6_fill_ifmcaddr(skb, ifmca, &fillargs); + err = inet6_fill_ifmcaddr(skb, ifmca, fillargs); if (err < 0) break; } break; case ANYCAST_ADDR: - fillargs.event = RTM_GETANYCAST; + fillargs->event = RTM_GETANYCAST; /* anycast address */ for (ifaca = idev->ac_list; ifaca; ifaca = ifaca->aca_next, ip_idx++) { if (ip_idx < s_ip_idx) continue; - err = inet6_fill_ifacaddr(skb, ifaca, &fillargs); + err = inet6_fill_ifacaddr(skb, ifaca, fillargs); if (err < 0) break; } @@ -5005,10 +5001,16 @@ static int in6_dump_addrs(struct inet6_dev *idev, struct sk_buff *skb, static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, enum addr_type_t type) { + struct inet6_fill_args fillargs = { + .portid = NETLINK_CB(cb->skb).portid, + .seq = cb->nlh->nlmsg_seq, + .flags = NLM_F_MULTI, + .netnsid = -1, + .type = type, + }; struct net *net = sock_net(skb->sk); struct nlattr *tb[IFA_MAX+1]; struct net *tgt_net = net; - int netnsid = -1; int h, s_h; int idx, ip_idx; int s_idx, s_ip_idx; @@ -5023,9 +5025,10 @@ static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, if (nlmsg_parse(cb->nlh, sizeof(struct ifaddrmsg), tb, IFA_MAX, ifa_ipv6_policy, cb->extack) >= 0) { if (tb[IFA_TARGET_NETNSID]) { - netnsid = nla_get_s32(tb[IFA_TARGET_NETNSID]); + fillargs.netnsid = nla_get_s32(tb[IFA_TARGET_NETNSID]); - tgt_net = rtnl_get_net_ns_capable(skb->sk, netnsid); + tgt_net = rtnl_get_net_ns_capable(skb->sk, + fillargs.netnsid); if (IS_ERR(tgt_net)) return PTR_ERR(tgt_net); } @@ -5046,8 +5049,8 @@ static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, if (!idev) goto cont; - if (in6_dump_addrs(idev, skb, cb, type, - s_ip_idx, &ip_idx, netnsid) < 0) + if (in6_dump_addrs(idev, skb, cb, s_ip_idx, &ip_idx, + &fillargs) < 0) goto done; cont: idx++; @@ -5058,7 +5061,7 @@ static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, cb->args[0] = h; cb->args[1] = idx; cb->args[2] = ip_idx; - if (netnsid >= 0) + if (fillargs.netnsid >= 0) put_net(tgt_net); return skb->len; From 89d35528d17d25819a755a2b52931e911baebc66 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:27 -0700 Subject: [PATCH 06/23] netlink: Add new socket option to enable strict checking on dumps Add a new socket option, NETLINK_DUMP_STRICT_CHK, that userspace can use via setsockopt to request strict checking of headers and attributes on dump requests. To get dump features such as kernel side filtering based on data in the header or attributes appended to the dump request, userspace must call setsockopt() for NETLINK_DUMP_STRICT_CHK and a non-zero value. Since the netlink sock and its flags are private to the af_netlink code, the strict checking flag is passed to dump handlers via a flag in the netlink_callback struct. For old userspace on new kernel there is no impact as all of the data checks in later patches are wrapped in a check on the new strict flag. For new userspace on old kernel, the setsockopt will fail and even if new userspace sets data in the headers and appended attributes the kernel will silently ignore it. Moving forward when the setsockopt succeeds, the new userspace on old kernel means the dump request can pass an attribute the kernel does not understand. The dump will then fail as the older kernel does not understand it. New userspace on new kernel setting the socket option gets the benefit of the improved data dump. Kernel side the NETLINK_DUMP_STRICT_CHK uapi is converted to a generic NETLINK_F_STRICT_CHK flag which can potentially be leveraged for tighter checking on the NEW, DEL, and SET commands. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- include/linux/netlink.h | 1 + include/uapi/linux/netlink.h | 1 + net/netlink/af_netlink.c | 21 ++++++++++++++++++++- net/netlink/af_netlink.h | 1 + 4 files changed, 23 insertions(+), 1 deletion(-) diff --git a/include/linux/netlink.h b/include/linux/netlink.h index 88c8a2d83eb3..72580f1a72a2 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -179,6 +179,7 @@ struct netlink_callback { struct netlink_ext_ack *extack; u16 family; u16 min_dump_alloc; + bool strict_check; unsigned int prev_seq, seq; long args[6]; }; diff --git a/include/uapi/linux/netlink.h b/include/uapi/linux/netlink.h index 776bc92e9118..486ed1f0c0bc 100644 --- a/include/uapi/linux/netlink.h +++ b/include/uapi/linux/netlink.h @@ -155,6 +155,7 @@ enum nlmsgerr_attrs { #define NETLINK_LIST_MEMBERSHIPS 9 #define NETLINK_CAP_ACK 10 #define NETLINK_EXT_ACK 11 +#define NETLINK_DUMP_STRICT_CHK 12 struct nl_pktinfo { __u32 group; diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 7ac585f33a9e..e613a9f89600 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -1706,6 +1706,13 @@ static int netlink_setsockopt(struct socket *sock, int level, int optname, nlk->flags &= ~NETLINK_F_EXT_ACK; err = 0; break; + case NETLINK_DUMP_STRICT_CHK: + if (val) + nlk->flags |= NETLINK_F_STRICT_CHK; + else + nlk->flags &= ~NETLINK_F_STRICT_CHK; + err = 0; + break; default: err = -ENOPROTOOPT; } @@ -1799,6 +1806,15 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname, return -EFAULT; err = 0; break; + case NETLINK_DUMP_STRICT_CHK: + if (len < sizeof(int)) + return -EINVAL; + len = sizeof(int); + val = nlk->flags & NETLINK_F_STRICT_CHK ? 1 : 0; + if (put_user(len, optlen) || put_user(val, optval)) + return -EFAULT; + err = 0; + break; default: err = -ENOPROTOOPT; } @@ -2282,9 +2298,9 @@ int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, const struct nlmsghdr *nlh, struct netlink_dump_control *control) { + struct netlink_sock *nlk, *nlk2; struct netlink_callback *cb; struct sock *sk; - struct netlink_sock *nlk; int ret; refcount_inc(&skb->users); @@ -2318,6 +2334,9 @@ int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, cb->min_dump_alloc = control->min_dump_alloc; cb->skb = skb; + nlk2 = nlk_sk(NETLINK_CB(skb).sk); + cb->strict_check = !!(nlk2->flags & NETLINK_F_STRICT_CHK); + if (control->start) { ret = control->start(cb); if (ret) diff --git a/net/netlink/af_netlink.h b/net/netlink/af_netlink.h index 962de7b3c023..5f454c8de6a4 100644 --- a/net/netlink/af_netlink.h +++ b/net/netlink/af_netlink.h @@ -15,6 +15,7 @@ #define NETLINK_F_LISTEN_ALL_NSID 0x10 #define NETLINK_F_CAP_ACK 0x20 #define NETLINK_F_EXT_ACK 0x40 +#define NETLINK_F_STRICT_CHK 0x80 #define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8) #define NLGRPLONGS(x) (NLGRPSZ(x)/sizeof(unsigned long)) From c33078e3dfb194489b2f0875f078dc76647cfecf Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:28 -0700 Subject: [PATCH 07/23] net/ipv4: Update inet_dump_ifaddr for strict data checking Update inet_dump_ifaddr for strict data checking. If the flag is set, the dump request is expected to have an ifaddrmsg struct as the header potentially followed by one or more attributes. Any data passed in the header or as an attribute is taken as a request to influence the data returned. Only values supported by the dump handler are allowed to be non-0 or set in the request. At the moment only the IFA_TARGET_NETNSID attribute is supported. Follow on patches can support for other fields (e.g., honor ifa_index and only return data for the given device index). Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- net/ipv4/devinet.c | 72 +++++++++++++++++++++++++++++++++++++++------- 1 file changed, 61 insertions(+), 11 deletions(-) diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index ab2b11df5ea4..6f2bbd04e950 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -1660,17 +1660,70 @@ static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa, return -EMSGSIZE; } +static int inet_valid_dump_ifaddr_req(const struct nlmsghdr *nlh, + struct inet_fill_args *fillargs, + struct net **tgt_net, struct sock *sk, + struct netlink_ext_ack *extack) +{ + struct nlattr *tb[IFA_MAX+1]; + struct ifaddrmsg *ifm; + int err, i; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) { + NL_SET_ERR_MSG(extack, "ipv4: Invalid header for address dump request"); + return -EINVAL; + } + + ifm = nlmsg_data(nlh); + if (ifm->ifa_prefixlen || ifm->ifa_flags || ifm->ifa_scope) { + NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for address dump request"); + return -EINVAL; + } + if (ifm->ifa_index) { + NL_SET_ERR_MSG(extack, "ipv4: Filter by device index not supported for address dump"); + return -EINVAL; + } + + err = nlmsg_parse_strict(nlh, sizeof(*ifm), tb, IFA_MAX, + ifa_ipv4_policy, extack); + if (err < 0) + return err; + + for (i = 0; i <= IFA_MAX; ++i) { + if (!tb[i]) + continue; + + if (i == IFA_TARGET_NETNSID) { + struct net *net; + + fillargs->netnsid = nla_get_s32(tb[i]); + + net = rtnl_get_net_ns_capable(sk, fillargs->netnsid); + if (IS_ERR(net)) { + NL_SET_ERR_MSG(extack, "ipv4: Invalid target network namespace id"); + return PTR_ERR(net); + } + *tgt_net = net; + } else { + NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in dump request"); + return -EINVAL; + } + } + + return 0; +} + static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb) { + const struct nlmsghdr *nlh = cb->nlh; struct inet_fill_args fillargs = { .portid = NETLINK_CB(cb->skb).portid, - .seq = cb->nlh->nlmsg_seq, + .seq = nlh->nlmsg_seq, .event = RTM_NEWADDR, .flags = NLM_F_MULTI, .netnsid = -1, }; struct net *net = sock_net(skb->sk); - struct nlattr *tb[IFA_MAX+1]; struct net *tgt_net = net; int h, s_h; int idx, s_idx; @@ -1684,16 +1737,13 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb) s_idx = idx = cb->args[1]; s_ip_idx = ip_idx = cb->args[2]; - if (nlmsg_parse(cb->nlh, sizeof(struct ifaddrmsg), tb, IFA_MAX, - ifa_ipv4_policy, cb->extack) >= 0) { - if (tb[IFA_TARGET_NETNSID]) { - fillargs.netnsid = nla_get_s32(tb[IFA_TARGET_NETNSID]); + if (cb->strict_check) { + int err; - tgt_net = rtnl_get_net_ns_capable(skb->sk, - fillargs.netnsid); - if (IS_ERR(tgt_net)) - return PTR_ERR(tgt_net); - } + err = inet_valid_dump_ifaddr_req(nlh, &fillargs, &tgt_net, + skb->sk, cb->extack); + if (err < 0) + return err; } for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) { From ed6eff11790a5bf1ce9b0421667e46ab1cf368f4 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:29 -0700 Subject: [PATCH 08/23] net/ipv6: Update inet6_dump_addr for strict data checking Update inet6_dump_addr for strict data checking. If the flag is set, the dump request is expected to have an ifaddrmsg struct as the header potentially followed by one or more attributes. Any data passed in the header or as an attribute is taken as a request to influence the data returned. Only values suppored by the dump handler are allowed to be non-0 or set in the request. At the moment only the IFA_TARGET_NETNSID attribute is supported. Follow on patches can add support for other fields (e.g., honor ifa_index and only return data for the given device index). Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 69 ++++++++++++++++++++++++++++++++++++++------- 1 file changed, 59 insertions(+), 10 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index afa279170ba5..095d3f56f0a9 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -4998,9 +4998,62 @@ static int in6_dump_addrs(struct inet6_dev *idev, struct sk_buff *skb, return err; } +static int inet6_valid_dump_ifaddr_req(const struct nlmsghdr *nlh, + struct inet6_fill_args *fillargs, + struct net **tgt_net, struct sock *sk, + struct netlink_ext_ack *extack) +{ + struct nlattr *tb[IFA_MAX+1]; + struct ifaddrmsg *ifm; + int err, i; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) { + NL_SET_ERR_MSG_MOD(extack, "Invalid header for address dump request"); + return -EINVAL; + } + + ifm = nlmsg_data(nlh); + if (ifm->ifa_prefixlen || ifm->ifa_flags || ifm->ifa_scope) { + NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for address dump request"); + return -EINVAL; + } + if (ifm->ifa_index) { + NL_SET_ERR_MSG_MOD(extack, "Filter by device index not supported for address dump"); + return -EINVAL; + } + + err = nlmsg_parse_strict(nlh, sizeof(*ifm), tb, IFA_MAX, + ifa_ipv6_policy, extack); + if (err < 0) + return err; + + for (i = 0; i <= IFA_MAX; ++i) { + if (!tb[i]) + continue; + + if (i == IFA_TARGET_NETNSID) { + struct net *net; + + fillargs->netnsid = nla_get_s32(tb[i]); + net = rtnl_get_net_ns_capable(sk, fillargs->netnsid); + if (IS_ERR(net)) { + NL_SET_ERR_MSG_MOD(extack, "Invalid target network namespace id"); + return PTR_ERR(net); + } + *tgt_net = net; + } else { + NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in dump request"); + return -EINVAL; + } + } + + return 0; +} + static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, enum addr_type_t type) { + const struct nlmsghdr *nlh = cb->nlh; struct inet6_fill_args fillargs = { .portid = NETLINK_CB(cb->skb).portid, .seq = cb->nlh->nlmsg_seq, @@ -5009,7 +5062,6 @@ static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, .type = type, }; struct net *net = sock_net(skb->sk); - struct nlattr *tb[IFA_MAX+1]; struct net *tgt_net = net; int h, s_h; int idx, ip_idx; @@ -5022,16 +5074,13 @@ static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, s_idx = idx = cb->args[1]; s_ip_idx = ip_idx = cb->args[2]; - if (nlmsg_parse(cb->nlh, sizeof(struct ifaddrmsg), tb, IFA_MAX, - ifa_ipv6_policy, cb->extack) >= 0) { - if (tb[IFA_TARGET_NETNSID]) { - fillargs.netnsid = nla_get_s32(tb[IFA_TARGET_NETNSID]); + if (cb->strict_check) { + int err; - tgt_net = rtnl_get_net_ns_capable(skb->sk, - fillargs.netnsid); - if (IS_ERR(tgt_net)) - return PTR_ERR(tgt_net); - } + err = inet6_valid_dump_ifaddr_req(nlh, &fillargs, &tgt_net, + skb->sk, cb->extack); + if (err < 0) + return err; } rcu_read_lock(); From 905cf0abe8c2c892313f08e38d808eee4e794987 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:30 -0700 Subject: [PATCH 09/23] rtnetlink: Update rtnl_dump_ifinfo for strict data checking Update rtnl_dump_ifinfo for strict data checking. If the flag is set, the dump request is expected to have an ifinfomsg struct as the header potentially followed by one or more attributes. Any data passed in the header or as an attribute is taken as a request to influence the data returned. Only values supported by the dump handler are allowed to be non-0 or set in the request. At the moment only the IFA_TARGET_NETNSID, IFLA_EXT_MASK, IFLA_MASTER, and IFLA_LINKINFO attributes are supported. Existing code does not fail the dump if nlmsg_parse fails. That behavior is kept for non-strict checking. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- net/core/rtnetlink.c | 119 +++++++++++++++++++++++++++++++------------ 1 file changed, 86 insertions(+), 33 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 4486e8b7d9d0..12fd52105005 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1878,8 +1878,52 @@ struct net *rtnl_get_net_ns_capable(struct sock *sk, int netnsid) } EXPORT_SYMBOL_GPL(rtnl_get_net_ns_capable); +static int rtnl_valid_dump_ifinfo_req(const struct nlmsghdr *nlh, + bool strict_check, struct nlattr **tb, + struct netlink_ext_ack *extack) +{ + int hdrlen; + + if (strict_check) { + struct ifinfomsg *ifm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) { + NL_SET_ERR_MSG(extack, "Invalid header for link dump"); + return -EINVAL; + } + + ifm = nlmsg_data(nlh); + if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags || + ifm->ifi_change) { + NL_SET_ERR_MSG(extack, "Invalid values in header for link dump request"); + return -EINVAL; + } + if (ifm->ifi_index) { + NL_SET_ERR_MSG(extack, "Filter by device index not supported for link dumps"); + return -EINVAL; + } + + return nlmsg_parse_strict(nlh, sizeof(*ifm), tb, IFLA_MAX, + ifla_policy, extack); + } + + /* A hack to preserve kernel<->userspace interface. + * The correct header is ifinfomsg. It is consistent with rtnl_getlink. + * However, before Linux v3.9 the code here assumed rtgenmsg and that's + * what iproute2 < v3.9.0 used. + * We can detect the old iproute2. Even including the IFLA_EXT_MASK + * attribute, its netlink message is shorter than struct ifinfomsg. + */ + hdrlen = nlmsg_len(nlh) < sizeof(struct ifinfomsg) ? + sizeof(struct rtgenmsg) : sizeof(struct ifinfomsg); + + return nlmsg_parse(nlh, hdrlen, tb, IFLA_MAX, ifla_policy, extack); +} + static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) { + struct netlink_ext_ack *extack = cb->extack; + const struct nlmsghdr *nlh = cb->nlh; struct net *net = sock_net(skb->sk); struct net *tgt_net = net; int h, s_h; @@ -1892,44 +1936,54 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) unsigned int flags = NLM_F_MULTI; int master_idx = 0; int netnsid = -1; - int err; - int hdrlen; + int err, i; s_h = cb->args[0]; s_idx = cb->args[1]; - /* A hack to preserve kernel<->userspace interface. - * The correct header is ifinfomsg. It is consistent with rtnl_getlink. - * However, before Linux v3.9 the code here assumed rtgenmsg and that's - * what iproute2 < v3.9.0 used. - * We can detect the old iproute2. Even including the IFLA_EXT_MASK - * attribute, its netlink message is shorter than struct ifinfomsg. - */ - hdrlen = nlmsg_len(cb->nlh) < sizeof(struct ifinfomsg) ? - sizeof(struct rtgenmsg) : sizeof(struct ifinfomsg); + err = rtnl_valid_dump_ifinfo_req(nlh, cb->strict_check, tb, extack); + if (err < 0) { + if (cb->strict_check) + return err; - if (nlmsg_parse(cb->nlh, hdrlen, tb, IFLA_MAX, - ifla_policy, cb->extack) >= 0) { - if (tb[IFLA_TARGET_NETNSID]) { - netnsid = nla_get_s32(tb[IFLA_TARGET_NETNSID]); - tgt_net = rtnl_get_net_ns_capable(skb->sk, netnsid); - if (IS_ERR(tgt_net)) - return PTR_ERR(tgt_net); - } - - if (tb[IFLA_EXT_MASK]) - ext_filter_mask = nla_get_u32(tb[IFLA_EXT_MASK]); - - if (tb[IFLA_MASTER]) - master_idx = nla_get_u32(tb[IFLA_MASTER]); - - if (tb[IFLA_LINKINFO]) - kind_ops = linkinfo_to_kind_ops(tb[IFLA_LINKINFO]); - - if (master_idx || kind_ops) - flags |= NLM_F_DUMP_FILTERED; + goto walk_entries; } + for (i = 0; i <= IFLA_MAX; ++i) { + if (!tb[i]) + continue; + + /* new attributes should only be added with strict checking */ + switch (i) { + case IFLA_TARGET_NETNSID: + netnsid = nla_get_s32(tb[i]); + tgt_net = rtnl_get_net_ns_capable(skb->sk, netnsid); + if (IS_ERR(tgt_net)) { + NL_SET_ERR_MSG(extack, "Invalid target network namespace id"); + return PTR_ERR(tgt_net); + } + break; + case IFLA_EXT_MASK: + ext_filter_mask = nla_get_u32(tb[i]); + break; + case IFLA_MASTER: + master_idx = nla_get_u32(tb[i]); + break; + case IFLA_LINKINFO: + kind_ops = linkinfo_to_kind_ops(tb[i]); + break; + default: + if (cb->strict_check) { + NL_SET_ERR_MSG(extack, "Unsupported attribute in link dump request"); + return -EINVAL; + } + } + } + + if (master_idx || kind_ops) + flags |= NLM_F_DUMP_FILTERED; + +walk_entries: for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) { idx = 0; head = &tgt_net->dev_index_head[h]; @@ -1941,8 +1995,7 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) err = rtnl_fill_ifinfo(skb, dev, net, RTM_NEWLINK, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, 0, - flags, + nlh->nlmsg_seq, 0, flags, ext_filter_mask, 0, NULL, 0, netnsid); From 2d011be8c07b50e8b3699d06ee11af5f5914b09a Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:31 -0700 Subject: [PATCH 10/23] rtnetlink: Update rtnl_bridge_getlink for strict data checking Update rtnl_bridge_getlink for strict data checking. If the flag is set, the dump request is expected to have an ifinfomsg struct as the header potentially followed by one or more attributes. Any data passed in the header or as an attribute is taken as a request to influence the data returned. Only values supported by the dump handler are allowed to be non-0 or set in the request. At the moment only the IFLA_EXT_MASK attribute is supported. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- net/core/rtnetlink.c | 70 ++++++++++++++++++++++++++++++++++++-------- 1 file changed, 57 insertions(+), 13 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 12fd52105005..e38e1f178611 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -4021,28 +4021,72 @@ int ndo_dflt_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq, } EXPORT_SYMBOL_GPL(ndo_dflt_bridge_getlink); +static int valid_bridge_getlink_req(const struct nlmsghdr *nlh, + bool strict_check, u32 *filter_mask, + struct netlink_ext_ack *extack) +{ + struct nlattr *tb[IFLA_MAX+1]; + int err, i; + + if (strict_check) { + struct ifinfomsg *ifm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) { + NL_SET_ERR_MSG(extack, "Invalid header for bridge link dump"); + return -EINVAL; + } + + ifm = nlmsg_data(nlh); + if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags || + ifm->ifi_change || ifm->ifi_index) { + NL_SET_ERR_MSG(extack, "Invalid values in header for bridge link dump request"); + return -EINVAL; + } + + err = nlmsg_parse_strict(nlh, sizeof(struct ifinfomsg), tb, + IFLA_MAX, ifla_policy, extack); + } else { + err = nlmsg_parse(nlh, sizeof(struct ifinfomsg), tb, + IFLA_MAX, ifla_policy, extack); + } + if (err < 0) + return err; + + /* new attributes should only be added with strict checking */ + for (i = 0; i <= IFLA_MAX; ++i) { + if (!tb[i]) + continue; + + switch (i) { + case IFLA_EXT_MASK: + *filter_mask = nla_get_u32(tb[i]); + break; + default: + if (strict_check) { + NL_SET_ERR_MSG(extack, "Unsupported attribute in bridge link dump request"); + return -EINVAL; + } + } + } + + return 0; +} + static int rtnl_bridge_getlink(struct sk_buff *skb, struct netlink_callback *cb) { + const struct nlmsghdr *nlh = cb->nlh; struct net *net = sock_net(skb->sk); struct net_device *dev; int idx = 0; u32 portid = NETLINK_CB(cb->skb).portid; - u32 seq = cb->nlh->nlmsg_seq; + u32 seq = nlh->nlmsg_seq; u32 filter_mask = 0; int err; - if (nlmsg_len(cb->nlh) > sizeof(struct ifinfomsg)) { - struct nlattr *extfilt; - - extfilt = nlmsg_find_attr(cb->nlh, sizeof(struct ifinfomsg), - IFLA_EXT_MASK); - if (extfilt) { - if (nla_len(extfilt) < sizeof(filter_mask)) - return -EINVAL; - - filter_mask = nla_get_u32(extfilt); - } - } + err = valid_bridge_getlink_req(nlh, cb->strict_check, &filter_mask, + cb->extack); + if (err < 0 && cb->strict_check) + return err; rcu_read_lock(); for_each_netdev_rcu(net, dev) { From 841891ec0c65d9ec81b3c56975d61ecc5b6ca365 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:32 -0700 Subject: [PATCH 11/23] rtnetlink: Update rtnl_stats_dump for strict data checking Update rtnl_stats_dump for strict data checking. If the flag is set, the dump request is expected to have an if_stats_msg struct as the header. All elements of the struct are expected to be 0 except filter_mask which must be non-0 (legacy behavior). No attributes are supported. Signed-off-by: David Ahern Signed-off-by: David S. Miller --- net/core/rtnetlink.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index e38e1f178611..f6d2609cfa9f 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -4680,6 +4680,7 @@ static int rtnl_stats_get(struct sk_buff *skb, struct nlmsghdr *nlh, static int rtnl_stats_dump(struct sk_buff *skb, struct netlink_callback *cb) { + struct netlink_ext_ack *extack = cb->extack; int h, s_h, err, s_idx, s_idxattr, s_prividx; struct net *net = sock_net(skb->sk); unsigned int flags = NLM_F_MULTI; @@ -4696,13 +4697,32 @@ static int rtnl_stats_dump(struct sk_buff *skb, struct netlink_callback *cb) cb->seq = net->dev_base_seq; - if (nlmsg_len(cb->nlh) < sizeof(*ifsm)) + if (nlmsg_len(cb->nlh) < sizeof(*ifsm)) { + NL_SET_ERR_MSG(extack, "Invalid header for stats dump"); return -EINVAL; + } ifsm = nlmsg_data(cb->nlh); + + /* only requests using NLM_F_DUMP_PROPER_HDR can pass data to + * influence the dump. The legacy exception is filter_mask. + */ + if (cb->strict_check) { + if (ifsm->pad1 || ifsm->pad2 || ifsm->ifindex) { + NL_SET_ERR_MSG(extack, "Invalid values in header for stats dump request"); + return -EINVAL; + } + if (nlmsg_attrlen(cb->nlh, sizeof(*ifsm))) { + NL_SET_ERR_MSG(extack, "Invalid attributes after stats header"); + return -EINVAL; + } + } + filter_mask = ifsm->filter_mask; - if (!filter_mask) + if (!filter_mask) { + NL_SET_ERR_MSG(extack, "Filter mask must be set for stats dump"); return -EINVAL; + } for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) { idx = 0; From 786e0007e29a58f563bce744e958c692c7cbd435 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:33 -0700 Subject: [PATCH 12/23] rtnetlink: Update inet6_dump_ifinfo for strict data checking Update inet6_dump_ifinfo for strict data checking. If the flag is set, the dump request is expected to have an ifinfomsg struct as the header. All elements of the struct are expected to be 0 and no attributes can be appended. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 095d3f56f0a9..ce071d85ad00 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -5644,6 +5644,31 @@ static int inet6_fill_ifinfo(struct sk_buff *skb, struct inet6_dev *idev, return -EMSGSIZE; } +static int inet6_valid_dump_ifinfo(const struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct ifinfomsg *ifm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) { + NL_SET_ERR_MSG_MOD(extack, "Invalid header for link dump request"); + return -EINVAL; + } + + if (nlmsg_attrlen(nlh, sizeof(*ifm))) { + NL_SET_ERR_MSG_MOD(extack, "Invalid data after header"); + return -EINVAL; + } + + ifm = nlmsg_data(nlh); + if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags || + ifm->ifi_change || ifm->ifi_index) { + NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for dump request"); + return -EINVAL; + } + + return 0; +} + static int inet6_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) { struct net *net = sock_net(skb->sk); @@ -5653,6 +5678,16 @@ static int inet6_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) struct inet6_dev *idev; struct hlist_head *head; + /* only requests using strict checking can pass data to + * influence the dump + */ + if (cb->strict_check) { + int err = inet6_valid_dump_ifinfo(cb->nlh, cb->extack); + + if (err < 0) + return err; + } + s_h = cb->args[0]; s_idx = cb->args[1]; From 14fc5bb29fe78aaa1777cfee248339497e30c02e Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:34 -0700 Subject: [PATCH 13/23] rtnetlink: Update ipmr_rtm_dumplink for strict data checking Update ipmr_rtm_dumplink for strict data checking. If the flag is set, the dump request is expected to have an ifinfomsg struct as the header. All elements of the struct are expected to be 0 and no attributes can be appended. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- net/ipv4/ipmr.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 5660adcf7a04..e7322e407bb4 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -2710,6 +2710,31 @@ static bool ipmr_fill_vif(struct mr_table *mrt, u32 vifid, struct sk_buff *skb) return true; } +static int ipmr_valid_dumplink(const struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct ifinfomsg *ifm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) { + NL_SET_ERR_MSG(extack, "ipv4: Invalid header for ipmr link dump"); + return -EINVAL; + } + + if (nlmsg_attrlen(nlh, sizeof(*ifm))) { + NL_SET_ERR_MSG(extack, "Invalid data after header in ipmr link dump"); + return -EINVAL; + } + + ifm = nlmsg_data(nlh); + if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags || + ifm->ifi_change || ifm->ifi_index) { + NL_SET_ERR_MSG(extack, "Invalid values in header for ipmr link dump request"); + return -EINVAL; + } + + return 0; +} + static int ipmr_rtm_dumplink(struct sk_buff *skb, struct netlink_callback *cb) { struct net *net = sock_net(skb->sk); @@ -2718,6 +2743,13 @@ static int ipmr_rtm_dumplink(struct sk_buff *skb, struct netlink_callback *cb) unsigned int e = 0, s_e; struct mr_table *mrt; + if (cb->strict_check) { + int err = ipmr_valid_dumplink(cb->nlh, cb->extack); + + if (err < 0) + return err; + } + s_t = cb->args[0]; s_e = cb->args[1]; From e8ba330ac0c55004e775eab53fa1e748e5d71bdb Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:35 -0700 Subject: [PATCH 14/23] rtnetlink: Update fib dumps for strict data checking Add helper to check netlink message for route dumps. If the strict flag is set the dump request is expected to have an rtmsg struct as the header. All elements of the struct are expected to be 0 with the exception of rtm_flags (which is used by both ipv4 and ipv6 dumps) and no attributes can be appended. rtm_flags can only have RTM_F_CLONED and RTM_F_PREFIX set. Update inet_dump_fib, inet6_dump_fib, mpls_dump_routes, ipmr_rtm_dumproute, and ip6mr_rtm_dumproute to call this helper if strict data checking is enabled. Signed-off-by: David Ahern Signed-off-by: David S. Miller --- include/net/ip_fib.h | 2 ++ net/ipv4/fib_frontend.c | 42 +++++++++++++++++++++++++++++++++++++++-- net/ipv4/ipmr.c | 7 +++++++ net/ipv6/ip6_fib.c | 8 ++++++++ net/ipv6/ip6mr.c | 9 +++++++++ net/mpls/af_mpls.c | 8 ++++++++ 6 files changed, 74 insertions(+), 2 deletions(-) diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h index f7c109e37298..9846b79c9ee1 100644 --- a/include/net/ip_fib.h +++ b/include/net/ip_fib.h @@ -452,4 +452,6 @@ static inline void fib_proc_exit(struct net *net) u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr); +int ip_valid_fib_dump_req(const struct nlmsghdr *nlh, + struct netlink_ext_ack *extack); #endif /* _NET_FIB_H */ diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index 30e2bcc3ef2a..038f511c73fa 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -802,8 +802,40 @@ static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, return err; } +int ip_valid_fib_dump_req(const struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct rtmsg *rtm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { + NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request"); + return -EINVAL; + } + + rtm = nlmsg_data(nlh); + if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos || + rtm->rtm_table || rtm->rtm_protocol || rtm->rtm_scope || + rtm->rtm_type) { + NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request"); + return -EINVAL; + } + if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) { + NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request"); + return -EINVAL; + } + + if (nlmsg_attrlen(nlh, sizeof(*rtm))) { + NL_SET_ERR_MSG(extack, "Invalid data after header in FIB dump request"); + return -EINVAL; + } + + return 0; +} +EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req); + static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) { + const struct nlmsghdr *nlh = cb->nlh; struct net *net = sock_net(skb->sk); unsigned int h, s_h; unsigned int e = 0, s_e; @@ -811,8 +843,14 @@ static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) struct hlist_head *head; int dumped = 0, err; - if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) && - ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED) + if (cb->strict_check) { + err = ip_valid_fib_dump_req(nlh, cb->extack); + if (err < 0) + return err; + } + + if (nlmsg_len(nlh) >= sizeof(struct rtmsg) && + ((struct rtmsg *)nlmsg_data(nlh))->rtm_flags & RTM_F_CLONED) return skb->len; s_h = cb->args[0]; diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index e7322e407bb4..91b0d5671649 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -2527,6 +2527,13 @@ static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb) { + if (cb->strict_check) { + int err = ip_valid_fib_dump_req(cb->nlh, cb->extack); + + if (err < 0) + return err; + } + return mr_rtm_dumproute(skb, cb, ipmr_mr_table_iter, _ipmr_fill_mroute, &mfc_unres_lock); } diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index cf709eadc932..e14d244c551f 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -564,6 +564,7 @@ static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) { + const struct nlmsghdr *nlh = cb->nlh; struct net *net = sock_net(skb->sk); unsigned int h, s_h; unsigned int e = 0, s_e; @@ -573,6 +574,13 @@ static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) struct hlist_head *head; int res = 0; + if (cb->strict_check) { + int err = ip_valid_fib_dump_req(nlh, cb->extack); + + if (err < 0) + return err; + } + s_h = cb->args[0]; s_e = cb->args[1]; diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index 6f07b8380425..d7563ef76518 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -2457,6 +2457,15 @@ static void mrt6msg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt) static int ip6mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb) { + const struct nlmsghdr *nlh = cb->nlh; + + if (cb->strict_check) { + int err = ip_valid_fib_dump_req(nlh, cb->extack); + + if (err < 0) + return err; + } + return mr_rtm_dumproute(skb, cb, ip6mr_mr_table_iter, _ip6mr_fill_mroute, &mfc_unres_lock); } diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c index 55a30ee3d820..0458c8aa5c11 100644 --- a/net/mpls/af_mpls.c +++ b/net/mpls/af_mpls.c @@ -2017,6 +2017,7 @@ static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event, static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb) { + const struct nlmsghdr *nlh = cb->nlh; struct net *net = sock_net(skb->sk); struct mpls_route __rcu **platform_label; size_t platform_labels; @@ -2024,6 +2025,13 @@ static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb) ASSERT_RTNL(); + if (cb->strict_check) { + int err = ip_valid_fib_dump_req(nlh, cb->extack); + + if (err < 0) + return err; + } + index = cb->args[0]; if (index < MPLS_LABEL_FIRST_UNRESERVED) index = MPLS_LABEL_FIRST_UNRESERVED; From 51183d233b5a5f1cfe2a782c86d6fcfc187173fe Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:36 -0700 Subject: [PATCH 15/23] net/neighbor: Update neigh_dump_info for strict data checking Update neigh_dump_info for strict data checking. If the flag is set, the dump request is expected to have an ndmsg struct as the header potentially followed by one or more attributes. Any data passed in the header or as an attribute is taken as a request to influence the data returned. Only values supported by the dump handler are allowed to be non-0 or set in the request. At the moment only the NDA_IFINDEX and NDA_MASTER attributes are supported. Existing code does not fail the dump if nlmsg_parse fails. That behavior is kept for non-strict checking. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- net/core/neighbour.c | 82 ++++++++++++++++++++++++++++++++++++-------- 1 file changed, 67 insertions(+), 15 deletions(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index b06f794bf91e..7c8a3a0ee059 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -2426,11 +2426,73 @@ static int pneigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb, } +static int neigh_valid_dump_req(const struct nlmsghdr *nlh, + bool strict_check, + struct neigh_dump_filter *filter, + struct netlink_ext_ack *extack) +{ + struct nlattr *tb[NDA_MAX + 1]; + int err, i; + + if (strict_check) { + struct ndmsg *ndm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ndm))) { + NL_SET_ERR_MSG(extack, "Invalid header for neighbor dump request"); + return -EINVAL; + } + + ndm = nlmsg_data(nlh); + if (ndm->ndm_pad1 || ndm->ndm_pad2 || ndm->ndm_ifindex || + ndm->ndm_state || ndm->ndm_flags || ndm->ndm_type) { + NL_SET_ERR_MSG(extack, "Invalid values in header for neighbor dump request"); + return -EINVAL; + } + + err = nlmsg_parse_strict(nlh, sizeof(struct ndmsg), tb, NDA_MAX, + NULL, extack); + } else { + err = nlmsg_parse(nlh, sizeof(struct ndmsg), tb, NDA_MAX, + NULL, extack); + } + if (err < 0) + return err; + + for (i = 0; i <= NDA_MAX; ++i) { + if (!tb[i]) + continue; + + /* all new attributes should require strict_check */ + switch (i) { + case NDA_IFINDEX: + if (nla_len(tb[i]) != sizeof(u32)) { + NL_SET_ERR_MSG(extack, "Invalid IFINDEX attribute in neighbor dump request"); + return -EINVAL; + } + filter->dev_idx = nla_get_u32(tb[i]); + break; + case NDA_MASTER: + if (nla_len(tb[i]) != sizeof(u32)) { + NL_SET_ERR_MSG(extack, "Invalid MASTER attribute in neighbor dump request"); + return -EINVAL; + } + filter->master_idx = nla_get_u32(tb[i]); + break; + default: + if (strict_check) { + NL_SET_ERR_MSG(extack, "Unsupported attribute in neighbor dump request"); + return -EINVAL; + } + } + } + + return 0; +} + static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb) { const struct nlmsghdr *nlh = cb->nlh; struct neigh_dump_filter filter = {}; - struct nlattr *tb[NDA_MAX + 1]; struct neigh_table *tbl; int t, family, s_t; int proxy = 0; @@ -2445,20 +2507,10 @@ static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb) ((struct ndmsg *)nlmsg_data(nlh))->ndm_flags == NTF_PROXY) proxy = 1; - err = nlmsg_parse(nlh, sizeof(struct ndmsg), tb, NDA_MAX, NULL, - cb->extack); - if (!err) { - if (tb[NDA_IFINDEX]) { - if (nla_len(tb[NDA_IFINDEX]) != sizeof(u32)) - return -EINVAL; - filter.dev_idx = nla_get_u32(tb[NDA_IFINDEX]); - } - if (tb[NDA_MASTER]) { - if (nla_len(tb[NDA_MASTER]) != sizeof(u32)) - return -EINVAL; - filter.master_idx = nla_get_u32(tb[NDA_MASTER]); - } - } + err = neigh_valid_dump_req(nlh, cb->strict_check, &filter, cb->extack); + if (err < 0 && cb->strict_check) + return err; + s_t = cb->args[0]; for (t = 0; t < NEIGH_NR_TABLES; t++) { From 9632d47f6a88f7f075347b66b88c60df7e9eae05 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:37 -0700 Subject: [PATCH 16/23] net/neighbor: Update neightbl_dump_info for strict data checking Update neightbl_dump_info for strict data checking. If the flag is set, the dump request is expected to have an ndtmsg struct as the header. All elements of the struct are expected to be 0 and no attributes can be appended. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- net/core/neighbour.c | 38 +++++++++++++++++++++++++++++++++++--- 1 file changed, 35 insertions(+), 3 deletions(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 7c8a3a0ee059..dc1389b8beb1 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -2164,15 +2164,47 @@ static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh, return err; } +static int neightbl_valid_dump_info(const struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct ndtmsg *ndtm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ndtm))) { + NL_SET_ERR_MSG(extack, "Invalid header for neighbor table dump request"); + return -EINVAL; + } + + ndtm = nlmsg_data(nlh); + if (ndtm->ndtm_pad1 || ndtm->ndtm_pad2) { + NL_SET_ERR_MSG(extack, "Invalid values in header for neighbor table dump request"); + return -EINVAL; + } + + if (nlmsg_attrlen(nlh, sizeof(*ndtm))) { + NL_SET_ERR_MSG(extack, "Invalid data after header in neighbor table dump request"); + return -EINVAL; + } + + return 0; +} + static int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb) { + const struct nlmsghdr *nlh = cb->nlh; struct net *net = sock_net(skb->sk); int family, tidx, nidx = 0; int tbl_skip = cb->args[0]; int neigh_skip = cb->args[1]; struct neigh_table *tbl; - family = ((struct rtgenmsg *) nlmsg_data(cb->nlh))->rtgen_family; + if (cb->strict_check) { + int err = neightbl_valid_dump_info(nlh, cb->extack); + + if (err < 0) + return err; + } + + family = ((struct rtgenmsg *)nlmsg_data(nlh))->rtgen_family; for (tidx = 0; tidx < NEIGH_NR_TABLES; tidx++) { struct neigh_parms *p; @@ -2185,7 +2217,7 @@ static int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb) continue; if (neightbl_fill_info(skb, tbl, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, RTM_NEWNEIGHTBL, + nlh->nlmsg_seq, RTM_NEWNEIGHTBL, NLM_F_MULTI) < 0) break; @@ -2200,7 +2232,7 @@ static int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb) if (neightbl_fill_param_info(skb, tbl, p, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, + nlh->nlmsg_seq, RTM_NEWNEIGHTBL, NLM_F_MULTI) < 0) goto out; From f80f14c3649f491e23712a30f86b20b6069fb72e Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:38 -0700 Subject: [PATCH 17/23] net/namespace: Update rtnl_net_dumpid for strict data checking Update rtnl_net_dumpid for strict data checking. If the flag is set, the dump request is expected to have an rtgenmsg struct as the header which has the family as the only element. No data may be appended. Signed-off-by: David Ahern Signed-off-by: David S. Miller --- net/core/net_namespace.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 670c84b1bfc2..fefe72774aeb 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -853,6 +853,12 @@ static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb) .s_idx = cb->args[0], }; + if (cb->strict_check && + nlmsg_attrlen(cb->nlh, sizeof(struct rtgenmsg))) { + NL_SET_ERR_MSG(cb->extack, "Unknown data in network namespace id dump request"); + return -EINVAL; + } + spin_lock_bh(&net->nsid_lock); idr_for_each(&net->netns_ids, rtnl_net_dumpid_one, &net_cb); spin_unlock_bh(&net->nsid_lock); From 4a73e5e56d667e354926fe3f5f1aa75ff18bca51 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:39 -0700 Subject: [PATCH 18/23] net/fib_rules: Update fib_nl_dumprule for strict data checking Update fib_nl_dumprule for strict data checking. If the flag is set, the dump request is expected to have fib_rule_hdr struct as the header. All elements of the struct are expected to be 0 and no attributes can be appended. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- net/core/fib_rules.c | 36 +++++++++++++++++++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-) diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c index 0ff3953f64aa..ffbb827723a2 100644 --- a/net/core/fib_rules.c +++ b/net/core/fib_rules.c @@ -1063,13 +1063,47 @@ static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb, return err; } +static int fib_valid_dumprule_req(const struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct fib_rule_hdr *frh; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { + NL_SET_ERR_MSG(extack, "Invalid header for fib rule dump request"); + return -EINVAL; + } + + frh = nlmsg_data(nlh); + if (frh->dst_len || frh->src_len || frh->tos || frh->table || + frh->res1 || frh->res2 || frh->action || frh->flags) { + NL_SET_ERR_MSG(extack, + "Invalid values in header for fib rule dump request"); + return -EINVAL; + } + + if (nlmsg_attrlen(nlh, sizeof(*frh))) { + NL_SET_ERR_MSG(extack, "Invalid data after header in fib rule dump request"); + return -EINVAL; + } + + return 0; +} + static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb) { + const struct nlmsghdr *nlh = cb->nlh; struct net *net = sock_net(skb->sk); struct fib_rules_ops *ops; int idx = 0, family; - family = rtnl_msg_family(cb->nlh); + if (cb->strict_check) { + int err = fib_valid_dumprule_req(nlh, cb->extack); + + if (err < 0) + return err; + } + + family = rtnl_msg_family(nlh); if (family != AF_UNSPEC) { /* Protocol specific dump request */ ops = lookup_rules_ops(net, family); From f2ae64bb6ba5b6a6e2271094a03d098821f4a699 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:40 -0700 Subject: [PATCH 19/23] net/ipv6: Update ip6addrlbl_dump for strict data checking Update ip6addrlbl_dump for strict data checking. If the flag is set, the dump request is expected to have an ifaddrlblmsg struct as the header. All elements of the struct are expected to be 0 and no attributes can be appended. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- net/ipv6/addrlabel.c | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c index 1d6ced37ad71..0d1ee82ee55b 100644 --- a/net/ipv6/addrlabel.c +++ b/net/ipv6/addrlabel.c @@ -458,20 +458,52 @@ static int ip6addrlbl_fill(struct sk_buff *skb, return 0; } +static int ip6addrlbl_valid_dump_req(const struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct ifaddrlblmsg *ifal; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifal))) { + NL_SET_ERR_MSG_MOD(extack, "Invalid header for address label dump request"); + return -EINVAL; + } + + ifal = nlmsg_data(nlh); + if (ifal->__ifal_reserved || ifal->ifal_prefixlen || + ifal->ifal_flags || ifal->ifal_index || ifal->ifal_seq) { + NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for address label dump request"); + return -EINVAL; + } + + if (nlmsg_attrlen(nlh, sizeof(*ifal))) { + NL_SET_ERR_MSG_MOD(extack, "Invalid data after header for address label dump requewst"); + return -EINVAL; + } + + return 0; +} + static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb) { + const struct nlmsghdr *nlh = cb->nlh; struct net *net = sock_net(skb->sk); struct ip6addrlbl_entry *p; int idx = 0, s_idx = cb->args[0]; int err; + if (cb->strict_check) { + err = ip6addrlbl_valid_dump_req(nlh, cb->extack); + if (err < 0) + return err; + } + rcu_read_lock(); hlist_for_each_entry_rcu(p, &net->ipv6.ip6addrlbl_table.head, list) { if (idx >= s_idx) { err = ip6addrlbl_fill(skb, p, net->ipv6.ip6addrlbl_table.seq, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, + nlh->nlmsg_seq, RTM_NEWADDRLABEL, NLM_F_MULTI); if (err < 0) From addd383f5a0ba9bf8336be3cc8b7a2916c08a77a Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:41 -0700 Subject: [PATCH 20/23] net: Update netconf dump handlers for strict data checking Update inet_netconf_dump_devconf, inet6_netconf_dump_devconf, and mpls_netconf_dump_devconf for strict data checking. If the flag is set, the dump request is expected to have an netconfmsg struct as the header. The struct only has the family member and no attributes can be appended. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- net/ipv4/devinet.c | 22 +++++++++++++++++++--- net/ipv6/addrconf.c | 22 +++++++++++++++++++--- net/mpls/af_mpls.c | 18 +++++++++++++++++- 3 files changed, 55 insertions(+), 7 deletions(-) diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index 6f2bbd04e950..d122ebbe5980 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -2086,6 +2086,7 @@ static int inet_netconf_get_devconf(struct sk_buff *in_skb, static int inet_netconf_dump_devconf(struct sk_buff *skb, struct netlink_callback *cb) { + const struct nlmsghdr *nlh = cb->nlh; struct net *net = sock_net(skb->sk); int h, s_h; int idx, s_idx; @@ -2093,6 +2094,21 @@ static int inet_netconf_dump_devconf(struct sk_buff *skb, struct in_device *in_dev; struct hlist_head *head; + if (cb->strict_check) { + struct netlink_ext_ack *extack = cb->extack; + struct netconfmsg *ncm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ncm))) { + NL_SET_ERR_MSG(extack, "ipv4: Invalid header for netconf dump request"); + return -EINVAL; + } + + if (nlmsg_attrlen(nlh, sizeof(*ncm))) { + NL_SET_ERR_MSG(extack, "ipv4: Invalid data after header in netconf dump request"); + return -EINVAL; + } + } + s_h = cb->args[0]; s_idx = idx = cb->args[1]; @@ -2112,7 +2128,7 @@ static int inet_netconf_dump_devconf(struct sk_buff *skb, if (inet_netconf_fill_devconf(skb, dev->ifindex, &in_dev->cnf, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, + nlh->nlmsg_seq, RTM_NEWNETCONF, NLM_F_MULTI, NETCONFA_ALL) < 0) { @@ -2129,7 +2145,7 @@ static int inet_netconf_dump_devconf(struct sk_buff *skb, if (inet_netconf_fill_devconf(skb, NETCONFA_IFINDEX_ALL, net->ipv4.devconf_all, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, + nlh->nlmsg_seq, RTM_NEWNETCONF, NLM_F_MULTI, NETCONFA_ALL) < 0) goto done; @@ -2140,7 +2156,7 @@ static int inet_netconf_dump_devconf(struct sk_buff *skb, if (inet_netconf_fill_devconf(skb, NETCONFA_IFINDEX_DEFAULT, net->ipv4.devconf_dflt, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, + nlh->nlmsg_seq, RTM_NEWNETCONF, NLM_F_MULTI, NETCONFA_ALL) < 0) goto done; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index ce071d85ad00..2496b12bf721 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -666,6 +666,7 @@ static int inet6_netconf_get_devconf(struct sk_buff *in_skb, static int inet6_netconf_dump_devconf(struct sk_buff *skb, struct netlink_callback *cb) { + const struct nlmsghdr *nlh = cb->nlh; struct net *net = sock_net(skb->sk); int h, s_h; int idx, s_idx; @@ -673,6 +674,21 @@ static int inet6_netconf_dump_devconf(struct sk_buff *skb, struct inet6_dev *idev; struct hlist_head *head; + if (cb->strict_check) { + struct netlink_ext_ack *extack = cb->extack; + struct netconfmsg *ncm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ncm))) { + NL_SET_ERR_MSG_MOD(extack, "Invalid header for netconf dump request"); + return -EINVAL; + } + + if (nlmsg_attrlen(nlh, sizeof(*ncm))) { + NL_SET_ERR_MSG_MOD(extack, "Invalid data after header in netconf dump request"); + return -EINVAL; + } + } + s_h = cb->args[0]; s_idx = idx = cb->args[1]; @@ -692,7 +708,7 @@ static int inet6_netconf_dump_devconf(struct sk_buff *skb, if (inet6_netconf_fill_devconf(skb, dev->ifindex, &idev->cnf, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, + nlh->nlmsg_seq, RTM_NEWNETCONF, NLM_F_MULTI, NETCONFA_ALL) < 0) { @@ -709,7 +725,7 @@ static int inet6_netconf_dump_devconf(struct sk_buff *skb, if (inet6_netconf_fill_devconf(skb, NETCONFA_IFINDEX_ALL, net->ipv6.devconf_all, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, + nlh->nlmsg_seq, RTM_NEWNETCONF, NLM_F_MULTI, NETCONFA_ALL) < 0) goto done; @@ -720,7 +736,7 @@ static int inet6_netconf_dump_devconf(struct sk_buff *skb, if (inet6_netconf_fill_devconf(skb, NETCONFA_IFINDEX_DEFAULT, net->ipv6.devconf_dflt, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, + nlh->nlmsg_seq, RTM_NEWNETCONF, NLM_F_MULTI, NETCONFA_ALL) < 0) goto done; diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c index 0458c8aa5c11..7f891ffffc05 100644 --- a/net/mpls/af_mpls.c +++ b/net/mpls/af_mpls.c @@ -1263,6 +1263,7 @@ static int mpls_netconf_get_devconf(struct sk_buff *in_skb, static int mpls_netconf_dump_devconf(struct sk_buff *skb, struct netlink_callback *cb) { + const struct nlmsghdr *nlh = cb->nlh; struct net *net = sock_net(skb->sk); struct hlist_head *head; struct net_device *dev; @@ -1270,6 +1271,21 @@ static int mpls_netconf_dump_devconf(struct sk_buff *skb, int idx, s_idx; int h, s_h; + if (cb->strict_check) { + struct netlink_ext_ack *extack = cb->extack; + struct netconfmsg *ncm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ncm))) { + NL_SET_ERR_MSG_MOD(extack, "Invalid header for netconf dump request"); + return -EINVAL; + } + + if (nlmsg_attrlen(nlh, sizeof(*ncm))) { + NL_SET_ERR_MSG_MOD(extack, "Invalid data after header in netconf dump request"); + return -EINVAL; + } + } + s_h = cb->args[0]; s_idx = idx = cb->args[1]; @@ -1286,7 +1302,7 @@ static int mpls_netconf_dump_devconf(struct sk_buff *skb, goto cont; if (mpls_netconf_fill_devconf(skb, mdev, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, + nlh->nlmsg_seq, RTM_NEWNETCONF, NLM_F_MULTI, NETCONFA_ALL) < 0) { From c77b93641e7dc88ef4919d8126949e3ec3ffe407 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:42 -0700 Subject: [PATCH 21/23] net/bridge: Update br_mdb_dump for strict data checking Update br_mdb_dump for strict data checking. If the flag is set, the dump request is expected to have a br_port_msg struct as the header. All elements of the struct are expected to be 0 and no attributes can be appended. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- net/bridge/br_mdb.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c index a4a848bf827b..a7ea2d431714 100644 --- a/net/bridge/br_mdb.c +++ b/net/bridge/br_mdb.c @@ -162,6 +162,29 @@ static int br_mdb_fill_info(struct sk_buff *skb, struct netlink_callback *cb, return err; } +static int br_mdb_valid_dump_req(const struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct br_port_msg *bpm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*bpm))) { + NL_SET_ERR_MSG_MOD(extack, "Invalid header for mdb dump request"); + return -EINVAL; + } + + bpm = nlmsg_data(nlh); + if (bpm->ifindex) { + NL_SET_ERR_MSG_MOD(extack, "Filtering by device index is not supported for mdb dump request"); + return -EINVAL; + } + if (nlmsg_attrlen(nlh, sizeof(*bpm))) { + NL_SET_ERR_MSG(extack, "Invalid data after header in mdb dump request"); + return -EINVAL; + } + + return 0; +} + static int br_mdb_dump(struct sk_buff *skb, struct netlink_callback *cb) { struct net_device *dev; @@ -169,6 +192,13 @@ static int br_mdb_dump(struct sk_buff *skb, struct netlink_callback *cb) struct nlmsghdr *nlh = NULL; int idx = 0, s_idx; + if (cb->strict_check) { + int err = br_mdb_valid_dump_req(cb->nlh, cb->extack); + + if (err < 0) + return err; + } + s_idx = cb->args[0]; rcu_read_lock(); From 8dfbda19a21b30475b7e6dcf2141a98ed2a19af5 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:43 -0700 Subject: [PATCH 22/23] rtnetlink: Move input checking for rtnl_fdb_dump to helper Move the existing input checking for rtnl_fdb_dump into a helper, valid_fdb_dump_legacy. This function will retain the current logic that works around the 2 headers that userspace has been allowed to send up to this point. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- net/core/rtnetlink.c | 59 +++++++++++++++++++++++++++----------------- 1 file changed, 36 insertions(+), 23 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index f6d2609cfa9f..c7509c789fb6 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -3799,14 +3799,44 @@ int ndo_dflt_fdb_dump(struct sk_buff *skb, } EXPORT_SYMBOL(ndo_dflt_fdb_dump); +static int valid_fdb_dump_legacy(const struct nlmsghdr *nlh, + int *br_idx, int *brport_idx, + struct netlink_ext_ack *extack) +{ + struct ifinfomsg *ifm = nlmsg_data(nlh); + struct nlattr *tb[IFLA_MAX+1]; + int err; + + /* A hack to preserve kernel<->userspace interface. + * Before Linux v4.12 this code accepted ndmsg since iproute2 v3.3.0. + * However, ndmsg is shorter than ifinfomsg thus nlmsg_parse() bails. + * So, check for ndmsg with an optional u32 attribute (not used here). + * Fortunately these sizes don't conflict with the size of ifinfomsg + * with an optional attribute. + */ + if (nlmsg_len(nlh) != sizeof(struct ndmsg) && + (nlmsg_len(nlh) != sizeof(struct ndmsg) + + nla_attr_size(sizeof(u32)))) { + err = nlmsg_parse(nlh, sizeof(struct ifinfomsg), tb, IFLA_MAX, + ifla_policy, extack); + if (err < 0) { + return -EINVAL; + } else if (err == 0) { + if (tb[IFLA_MASTER]) + *br_idx = nla_get_u32(tb[IFLA_MASTER]); + } + + *brport_idx = ifm->ifi_index; + } + return 0; +} + static int rtnl_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb) { struct net_device *dev; - struct nlattr *tb[IFLA_MAX+1]; struct net_device *br_dev = NULL; const struct net_device_ops *ops = NULL; const struct net_device_ops *cops = NULL; - struct ifinfomsg *ifm = nlmsg_data(cb->nlh); struct net *net = sock_net(skb->sk); struct hlist_head *head; int brport_idx = 0; @@ -3816,27 +3846,10 @@ static int rtnl_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb) int err = 0; int fidx = 0; - /* A hack to preserve kernel<->userspace interface. - * Before Linux v4.12 this code accepted ndmsg since iproute2 v3.3.0. - * However, ndmsg is shorter than ifinfomsg thus nlmsg_parse() bails. - * So, check for ndmsg with an optional u32 attribute (not used here). - * Fortunately these sizes don't conflict with the size of ifinfomsg - * with an optional attribute. - */ - if (nlmsg_len(cb->nlh) != sizeof(struct ndmsg) && - (nlmsg_len(cb->nlh) != sizeof(struct ndmsg) + - nla_attr_size(sizeof(u32)))) { - err = nlmsg_parse(cb->nlh, sizeof(struct ifinfomsg), tb, - IFLA_MAX, ifla_policy, cb->extack); - if (err < 0) { - return -EINVAL; - } else if (err == 0) { - if (tb[IFLA_MASTER]) - br_idx = nla_get_u32(tb[IFLA_MASTER]); - } - - brport_idx = ifm->ifi_index; - } + err = valid_fdb_dump_legacy(cb->nlh, &br_idx, &brport_idx, + cb->extack); + if (err < 0) + return err; if (br_idx) { br_dev = __dev_get_by_index(net, br_idx); From 8c6e137fbc7f207cd1e3f3080bfad0d4fd538254 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:44 -0700 Subject: [PATCH 23/23] rtnetlink: Update rtnl_fdb_dump for strict data checking Update rtnl_fdb_dump for strict data checking. If the flag is set, the dump request is expected to have an ndmsg struct as the header potentially followed by one or more attributes. Any data passed in the header or as an attribute is taken as a request to influence the data returned. Only values supported by the dump handler are allowed to be non-0 or set in the request. At the moment only the NDA_IFINDEX and NDA_MASTER attributes are supported. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- net/core/rtnetlink.c | 62 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 60 insertions(+), 2 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index c7509c789fb6..c894c4af8981 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -3799,6 +3799,60 @@ int ndo_dflt_fdb_dump(struct sk_buff *skb, } EXPORT_SYMBOL(ndo_dflt_fdb_dump); +static int valid_fdb_dump_strict(const struct nlmsghdr *nlh, + int *br_idx, int *brport_idx, + struct netlink_ext_ack *extack) +{ + struct nlattr *tb[NDA_MAX + 1]; + struct ndmsg *ndm; + int err, i; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ndm))) { + NL_SET_ERR_MSG(extack, "Invalid header for fdb dump request"); + return -EINVAL; + } + + ndm = nlmsg_data(nlh); + if (ndm->ndm_pad1 || ndm->ndm_pad2 || ndm->ndm_state || + ndm->ndm_flags || ndm->ndm_type) { + NL_SET_ERR_MSG(extack, "Invalid values in header for fbd dump request"); + return -EINVAL; + } + + err = nlmsg_parse_strict(nlh, sizeof(struct ndmsg), tb, NDA_MAX, + NULL, extack); + if (err < 0) + return err; + + *brport_idx = ndm->ndm_ifindex; + for (i = 0; i <= NDA_MAX; ++i) { + if (!tb[i]) + continue; + + switch (i) { + case NDA_IFINDEX: + if (nla_len(tb[i]) != sizeof(u32)) { + NL_SET_ERR_MSG(extack, "Invalid IFINDEX attribute in fdb dump request"); + return -EINVAL; + } + *brport_idx = nla_get_u32(tb[NDA_IFINDEX]); + break; + case NDA_MASTER: + if (nla_len(tb[i]) != sizeof(u32)) { + NL_SET_ERR_MSG(extack, "Invalid MASTER attribute in fdb dump request"); + return -EINVAL; + } + *br_idx = nla_get_u32(tb[NDA_MASTER]); + break; + default: + NL_SET_ERR_MSG(extack, "Unsupported attribute in fdb dump request"); + return -EINVAL; + } + } + + return 0; +} + static int valid_fdb_dump_legacy(const struct nlmsghdr *nlh, int *br_idx, int *brport_idx, struct netlink_ext_ack *extack) @@ -3846,8 +3900,12 @@ static int rtnl_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb) int err = 0; int fidx = 0; - err = valid_fdb_dump_legacy(cb->nlh, &br_idx, &brport_idx, - cb->extack); + if (cb->strict_check) + err = valid_fdb_dump_strict(cb->nlh, &br_idx, &brport_idx, + cb->extack); + else + err = valid_fdb_dump_legacy(cb->nlh, &br_idx, &brport_idx, + cb->extack); if (err < 0) return err;