linux/net/core
Eric Dumazet 6bd4f355df ipv6: kill sk_dst_lock
While testing the np->opt RCU conversion, I found that UDP/IPv6 was
using a mixture of xchg() and sk_dst_lock to protect concurrent changes
to sk->sk_dst_cache, leading to possible corruptions and crashes.

ip6_sk_dst_lookup_flow() uses sk_dst_check() anyway, so the simplest
way to fix the mess is to remove sk_dst_lock completely, as we did for
IPv4.

__ip6_dst_store() and ip6_dst_store() share same implementation.

sk_setup_caps() being called with socket lock being held or not,
we have to use sk_dst_set() instead of __sk_dst_set()

Note that I had to move the "np->dst_cookie = rt6_get_cookie(rt);"
in ip6_dst_store() before the sk_setup_caps(sk, dst) call.

This is because ip6_dst_store() can be called from process context,
without any lock held.

As soon as the dst is installed in sk->sk_dst_cache, dst can be freed
from another cpu doing a concurrent ip6_dst_store()

Doing the dst dereference before doing the install is needed to make
sure no use after free would trigger.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-03 11:32:06 -05:00
..
Makefile lwtunnel: infrastructure for handling light weight tunnels like mpls 2015-07-21 10:39:03 -07:00
datagram.c net: rename SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA 2015-12-01 15:45:05 -05:00
dev.c net/core: revert "net: fix __netdev_update_features return.." and add comment 2015-11-17 15:25:45 -05:00
dev_addr_lists.c net: fix spelling for synchronized 2014-11-18 15:26:32 -05:00
dev_ioctl.c dev_ioctl: use sizeof(x) instead of sizeof x 2014-11-18 15:27:32 -05:00
drop_monitor.c net: Replace get_cpu_var through this_cpu_ptr 2014-08-26 13:45:47 -04:00
dst.c net: fix a race in dst_release() 2015-11-09 21:55:48 -05:00
ethtool.c ethtool: Use kcalloc instead of kmalloc for ethtool_get_strings 2015-10-14 19:00:20 -07:00
fib_rules.c fib_rules: fix fib rule dumps across multiple skbs 2015-09-24 15:21:54 -07:00
filter.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-10-20 06:08:27 -07:00
flow.c flow: Move __get_hash_from_flowi{4,6} into flow_dissector.c 2015-09-01 17:00:24 -07:00
flow_dissector.c flow_dissector: Use 'const' where possible. 2015-09-01 21:19:17 -07:00
gen_estimator.c net_sched: gen_estimator: extend pps limit 2015-07-08 13:59:20 -07:00
gen_stats.c gen_stats.c: Duplicate xstats buffer for later use 2015-02-19 15:45:53 -05:00
link_watch.c dev: introduce dev_get_iflink() 2015-04-02 14:04:59 -04:00
lwtunnel.c dst: Pass net into dst->output 2015-10-08 04:27:03 -07:00
neighbour.c net/neighbour: fix crash at dumping device-agnostic proxy entries 2015-12-03 00:07:51 -05:00
net-procfs.c rps: selective flow shedding during softnet overflow 2013-05-20 13:48:04 -07:00
net-sysfs.c switchdev: rename SWITCHDEV_ATTR_* enum values to SWITCHDEV_ATTR_ID_* 2015-10-03 04:49:37 -07:00
net-sysfs.h net: netdev_kobject_init: annotate with __init 2014-01-05 20:27:54 -05:00
net-traces.c net: FIB tracepoints 2015-08-29 13:05:16 -07:00
net_namespace.c netns: make nsid_lock per net 2015-05-17 23:41:11 -04:00
netclassid_cgroup.c cgroups: Allow dynamically changing net_classid 2015-11-23 12:13:46 -05:00
netevent.c netevent: remove automatic variable in register_netevent_notifier() 2015-05-31 00:03:21 -07:00
netpoll.c netpoll: Drop budget parameter from NAPI polling call hierarchy 2015-09-29 14:57:16 -07:00
netprio_cgroup.c cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes 2014-07-15 11:05:09 -04:00
pktgen.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-08-13 16:23:11 -07:00
ptp_classifier.c ptp: Change ptp_class to a proper bitmask 2015-11-03 11:08:22 -05:00
request_sock.c tcp: restore fastopen operations 2015-10-05 03:19:06 -07:00
rtnetlink.c rtnetlink: fix frame size warning in rtnl_fill_ifinfo 2015-11-17 15:25:44 -05:00
scm.c net, scm: fix PaX detected msg_controllen overflow in scm_detach_fds 2015-11-22 20:34:58 -05:00
secure_seq.c net: remove a sparse error in secure_dccpv6_sequence_number() 2015-05-25 22:55:37 -04:00
skbuff.c vlan: Fix untag operations of stacked vlans with REORDER_HEADER off 2015-11-17 14:38:35 -05:00
sock.c ipv6: kill sk_dst_lock 2015-12-03 11:32:06 -05:00
sock_diag.c net/core: make sock_diag.c explicitly non-modular 2015-10-09 07:52:27 -07:00
stream.c net: fix sock_wake_async() rcu protection 2015-12-01 15:45:05 -05:00
sysctl_net_core.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-03-20 18:51:09 -04:00
timestamping.c net: skb_defer_rx_timestamp should check for phydev before setting up classify 2015-07-09 14:17:15 -07:00
tso.c net: tso: add support for IPv6 2015-10-26 22:24:22 -07:00
utils.c net: move net_get_random_once to lib 2015-10-08 05:26:35 -07:00