android_kernel_samsung_msm8226/net/packet
Marissa Wall 7f03a90e40 BACKPORT: 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.

Bug: 69160446
Fixes: dc99f60069 ("packet: Add fanout support.")
Change-Id: I899f9b6bcbd1d4b033388ef22c472857574bfc30
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>
Signed-off-by: Marissa Wall <marissaw@google.com>
Signed-off-by: Siqi Lin <siqilin@google.com>
CVE-2017-15649
Signed-off-by: Kevin F. Haggerty <haggertk@lineageos.org>
2020-01-06 08:40:25 +01:00
..
Kconfig
Makefile
af_packet.c BACKPORT: packet: in packet_do_bind, test fanout with bind_lock held 2020-01-06 08:40:25 +01:00