linux/net/ipv4
Jonathon Reinhart 97684f0970 net: Make tcp_allowed_congestion_control readonly in non-init netns
Currently, tcp_allowed_congestion_control is global and writable;
writing to it in any net namespace will leak into all other net
namespaces.

tcp_available_congestion_control and tcp_allowed_congestion_control are
the only sysctls in ipv4_net_table (the per-netns sysctl table) with a
NULL data pointer; their handlers (proc_tcp_available_congestion_control
and proc_allowed_congestion_control) have no other way of referencing a
struct net. Thus, they operate globally.

Because ipv4_net_table does not use designated initializers, there is no
easy way to fix up this one "bad" table entry. However, the data pointer
updating logic shouldn't be applied to NULL pointers anyway, so we
instead force these entries to be read-only.

These sysctls used to exist in ipv4_table (init-net only), but they were
moved to the per-net ipv4_net_table, presumably without realizing that
tcp_allowed_congestion_control was writable and thus introduced a leak.

Because the intent of that commit was only to know (i.e. read) "which
congestion algorithms are available or allowed", this read-only solution
should be sufficient.

The logic added in recent commit
31c4d2f160eb: ("net: Ensure net namespace isolation of sysctls")
does not and cannot check for NULL data pointers, because
other table entries (e.g. /proc/sys/net/netfilter/nf_log/) have
.data=NULL but use other methods (.extra2) to access the struct net.

Fixes: 9cb8e048e5 ("net/ipv4/sysctl: show tcp_{allowed, available}_congestion_control in non-initial netns")
Signed-off-by: Jonathon Reinhart <jonathon.reinhart@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-13 14:42:51 -07:00
..
bpfilter net: Revert "net: optimize the sockptr_t for unified kernel/user address spaces" 2020-08-10 12:06:44 -07:00
netfilter netfilter: x_tables: fix compat match/target pad out-of-bound write 2021-04-13 00:18:57 +02:00
Kconfig net: ipv4: remove duplicate "the the" phrase in Kconfig text 2020-08-18 16:02:16 -07:00
Makefile udp_tunnel: add central NIC RX port offload infrastructure 2020-07-10 13:54:00 -07:00
af_inet.c net: remove cmsg restriction from io_uring based send/recvmsg calls 2021-02-23 20:32:11 -07:00
ah4.c xfrm: Use actual socket sk instead of skb socket for xfrm_output_resume 2021-03-03 09:32:52 +01:00
arp.c net: Exempt multicast addresses from five-second neighbor lifetime 2020-11-13 14:24:39 -08:00
bpf_tcp_ca.c bpf: Remove hard-coded btf_vmlinux assumption from BPF verifier 2020-12-03 17:38:21 -08:00
cipso_ipv4.c CIPSO: Fix unaligned memory access in cipso_v4_gentag_hdr 2021-03-05 13:00:38 -08:00
datagram.c inet: stop leaking jiffies on the wire 2019-11-01 14:57:52 -07:00
devinet.c ipv6: report errors for iftoken via netlink extack 2021-04-08 13:52:36 -07:00
esp4.c xfrm: Use actual socket sk instead of skb socket for xfrm_output_resume 2021-03-03 09:32:52 +01:00
esp4_offload.c xfrm: Provide private skb extensions for segmented and hw offloaded ESP packets 2021-03-29 09:14:12 +02:00
fib_frontend.c ipv4: Ignore ECN bits for fib lookups in fib_compute_spec_dst() 2020-12-28 14:44:32 -08:00
fib_lookup.h IPv4: Add "offload failed" indication to routes 2021-02-08 16:47:03 -08:00
fib_notifier.c net: fib_notifier: propagate extack down to the notifier block callback 2019-10-04 11:10:56 -07:00
fib_rules.c fib: use indirect call wrappers in the most common fib_rules_ops 2020-07-28 17:42:31 -07:00
fib_semantics.c IPv4: Add "offload failed" indication to routes 2021-02-08 16:47:03 -08:00
fib_trie.c IPv4: Extend 'fib_notify_on_flag_change' sysctl 2021-02-08 16:47:03 -08:00
fou.c genetlink: move to smaller ops wherever possible 2020-10-02 19:11:11 -07:00
gre_demux.c erspan: fix version 1 check in gre_parse_header() 2020-12-28 15:00:00 -08:00
gre_offload.c ip_gre: add csum offload support for gre header 2021-01-29 20:39:14 -08:00
icmp.c net: icmp: pass zeroed opts from icmp{,v6}_ndo_send before sending 2021-02-23 11:29:52 -08:00
igmp.c ip*_mc_gsfget(): lift copyout of struct group_filter into callers 2020-05-20 20:31:27 -04:00
inet_connection_sock.c tcp: relookup sock for RST+ACK packets handled by obsolete req sock 2021-03-15 14:34:29 -07:00
inet_diag.c inet_diag: Fix error path to cancel the meseage in inet_req_diag_fill() 2020-11-17 16:08:36 -08:00
inet_fragment.c inet: frags: batch fqdir destroy works 2020-12-12 15:08:54 -08:00
inet_hashtables.c tcp: add some entropy in __inet_hash_connect() 2021-02-11 13:13:05 -08:00
inet_timewait_sock.c net: Use generic ns_common::count 2020-08-19 14:06:36 +02:00
inetpeer.c inetpeer: use div64_ul() and clamp_val() calculate inet_peer_threshold 2021-03-01 13:32:12 -08:00
ip_forward.c ipv4: Revert removal of rt_uses_gateway 2019-09-20 18:23:33 -07:00
ip_fragment.c inet: frags: re-introduce skb coalescing for local delivery 2019-08-08 15:55:10 -07:00
ip_gre.c ipv4/ipv6: switch to dev_get_tstats64 2020-11-09 17:50:28 -08:00
ip_input.c net: use indirect call helpers for dst_input 2021-02-03 14:51:39 -08:00
ip_options.c net: clean up codestyle for net/ipv4 2020-08-25 06:28:02 -07:00
ip_output.c net: use indirect call helpers for dst_output 2021-02-03 14:51:39 -08:00
ip_sockglue.c net: Remove duplicated midx check against 0 2020-08-25 06:23:59 -07:00
ip_tunnel.c net: always use icmp{,v6}_ndo_send from ndo_start_xmit 2021-03-01 13:11:35 -08:00
ip_tunnel_core.c net: ip_tunnel: clean up endianness conversions 2021-01-08 19:25:35 -08:00
ip_vti.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec 2021-03-31 14:37:51 -07:00
ipcomp.c ipcomp: assign if_id to child tunnel from parent tunnel 2020-07-09 12:55:37 +02:00
ipconfig.c net: ipconfig: ic_dev can be NULL in ic_close_devs 2021-03-22 12:57:51 -07:00
ipip.c ipv4/ipv6: switch to dev_get_tstats64 2020-11-09 17:50:28 -08:00
ipmr.c ipmr: Use full VIF ID in netlink cache reports 2020-09-10 12:25:51 -07:00
ipmr_base.c net: fib_notifier: propagate extack down to the notifier block callback 2019-10-04 11:10:56 -07:00
metrics.c treewide: rename nla_strlcpy to nla_strscpy. 2020-11-16 08:08:54 -08:00
netfilter.c netfilter: use actual socket sk rather than skb sk when routing harder 2020-10-30 12:57:39 +01:00
netlink.c
nexthop.c nexthop: Do not flush blackhole nexthops when loopback goes down 2021-03-04 14:04:49 -08:00
ping.c lsm,selinux: pass flowi_common instead of flowi to the LSM hooks 2020-11-23 18:36:21 -05:00
proc.c net: proc: speedup /proc/net/netstat 2021-01-29 20:59:53 -08:00
protocol.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
raw.c lsm,selinux: pass flowi_common instead of flowi to the LSM hooks 2020-11-23 18:36:21 -05:00
raw_diag.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-12 22:34:48 -07:00
route.c net: Consolidate common blackhole dst ops 2021-03-10 12:24:18 -08:00
syncookies.c selinux/stable-5.11 PR 20201214 2020-12-16 11:01:04 -08:00
sysctl_net_ipv4.c net: Make tcp_allowed_congestion_control readonly in non-init netns 2021-04-13 14:42:51 -07:00
tcp.c tcp: add sanity tests to TCP_QUEUE_SEQ 2021-03-01 15:32:05 -08:00
tcp_bbr.c tcp: only postpone PROBE_RTT if RTT is < current min_rtt estimate 2020-11-17 11:03:22 -08:00
tcp_bic.c tcp: fix stretch ACK bugs in BIC 2020-03-16 18:26:54 -07:00
tcp_bpf.c bpf, sockmap: Ensure SO_RCVBUF memory is observed on ingress redirect 2020-11-18 00:12:34 +01:00
tcp_cdg.c
tcp_cong.c tcp: Set INET_ECN_xmit configuration in tcp_reinit_congestion_control 2020-11-20 18:09:47 -08:00
tcp_cubic.c tcp_cubic: use memset and offsetof init 2021-01-15 20:22:16 -08:00
tcp_dctcp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tcp_dctcp.h
tcp_diag.c inet_diag: Move the INET_DIAG_REQ_BYTECODE nlattr to cb->data 2020-02-27 18:50:19 -08:00
tcp_fastopen.c bpf: tcp: Add bpf_skops_established() 2020-08-24 14:35:00 -07:00
tcp_highspeed.c Replace HTTP links with HTTPS ones: IPv* 2020-07-06 13:23:03 -07:00
tcp_htcp.c Replace HTTP links with HTTPS ones: IPv* 2020-07-06 13:23:03 -07:00
tcp_hybla.c
tcp_illinois.c
tcp_input.c tcp: tcp_data_ready() must look at SOCK_DONE 2021-02-15 13:20:36 -08:00
tcp_ipv4.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-02-16 13:14:06 -08:00
tcp_lp.c net: ipv4: Fix some kerneldoc warnings in TCP Low Priority 2020-10-30 12:10:57 -07:00
tcp_metrics.c fixes-v5.11 2020-12-14 16:40:27 -08:00
tcp_minisocks.c tcp: relookup sock for RST+ACK packets handled by obsolete req sock 2021-03-15 14:34:29 -07:00
tcp_nv.c
tcp_offload.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tcp_output.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-01-28 17:09:31 -08:00
tcp_rate.c
tcp_recovery.c tcp: fix TLP timer not set when CA_STATE changes from DISORDER to OPEN 2021-01-23 21:33:01 -08:00
tcp_scalable.c net: ipv4: delete repeated words 2020-08-24 17:31:20 -07:00
tcp_timer.c tcp: make TCP_USER_TIMEOUT accurate for zero window probes 2021-01-23 19:32:51 -08:00
tcp_ulp.c bpf: sockmap: Only check ULP for TCP sockets 2020-03-09 22:34:58 +01:00
tcp_vegas.c tcp: use semicolons rather than commas to separate statements 2020-10-13 17:11:52 -07:00
tcp_vegas.h
tcp_veno.c Replace HTTP links with HTTPS ones: IPv* 2020-07-06 13:23:03 -07:00
tcp_westwood.c
tcp_yeah.c tcp: fix stretch ACK bugs in Yeah 2020-03-16 18:26:55 -07:00
tunnel4.c tunnel4: add cb_handler to struct xfrm_tunnel 2020-07-09 12:51:36 +02:00
udp.c net: udp: Add support for getsockopt(..., ..., UDP_GRO, ..., ...); 2021-04-01 15:50:50 -07:00
udp_bpf.c net: sk_msg: Simplify sk_psock initialization 2020-08-21 15:16:11 -07:00
udp_diag.c net: udp: remove redundant initialization in udp_dump_one 2020-11-09 16:42:49 -08:00
udp_impl.h net: pass a sockptr_t into ->setsockopt 2020-07-24 15:41:54 -07:00
udp_offload.c net: Fix gro aggregation for udp encaps with zero csum 2021-02-28 12:01:08 -08:00
udp_tunnel_core.c udp_tunnel: reshuffle NETIF_F_RX_UDP_TUNNEL_PORT checks 2021-01-07 12:53:29 -08:00
udp_tunnel_nic.c udp_tunnel: add the ability to share port tables 2020-09-28 12:50:12 -07:00
udp_tunnel_stub.c udp_tunnel: add central NIC RX port offload infrastructure 2020-07-10 13:54:00 -07:00
udplite.c net/ipv4: remove compat_ip_{get,set}sockopt 2020-07-19 18:16:41 -07:00
xfrm4_input.c xfrm: state: remove extract_input indirection from xfrm_state_afinfo 2020-05-06 09:40:08 +02:00
xfrm4_output.c xfrm: fix unused variable warning if CONFIG_NETFILTER=n 2020-05-11 15:12:27 +02:00
xfrm4_policy.c net: add bool confirm_neigh parameter for dst_ops.update_pmtu 2019-12-24 22:28:54 -08:00
xfrm4_protocol.c xfrm: add route lookup to xfrm4_rcv_encap 2019-12-09 09:59:07 +01:00
xfrm4_state.c xfrm: remove output_finish indirection from xfrm_state_afinfo 2020-05-06 09:40:08 +02:00
xfrm4_tunnel.c xfrm: interface: fix the priorities for ipip and ipv6 tunnels 2020-10-09 12:29:48 +02:00