android_kernel_oneplus_msm8998/net/packet
Willem de Bruijn 1b6c80e797 packet: in packet_do_bind, test fanout with bind_lock held
[ Upstream commit 4971613c1639d8e5f102c4e797c3bf8f83a5a69e ]

Once a socket has po->fanout set, it remains a member of the group
until it is destroyed. The prot_hook must be constant and identical
across sockets in the group.

If fanout_add races with packet_do_bind between the test of po->fanout
and taking the lock, the bind call may make type or dev inconsistent
with that of the fanout group.

Hold po->bind_lock when testing po->fanout to avoid this race.

I had to introduce artificial delay (local_bh_enable) to actually
observe the race.

Fixes: dc99f60069 ("packet: Add fanout support.")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-21 17:09:03 +02:00
..
af_packet.c packet: in packet_do_bind, test fanout with bind_lock held 2017-10-21 17:09:03 +02:00
diag.c netlink: make nlmsg_end() and genlmsg_end() void 2015-01-18 01:03:45 -05:00
internal.h packet: add classic BPF fanout mode 2015-08-17 14:22:47 -07:00
Kconfig packet: Diag core and basic socket info dumping 2012-08-14 16:56:33 -07:00
Makefile packet: Diag core and basic socket info dumping 2012-08-14 16:56:33 -07:00