From: Philip Pettersson Date: Wed, 30 Nov 2016 22:55:36 +0000 (-0800) Subject: packet: fix race condition in packet_set_ring X-Git-Tag: v3.2.85~31 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a9aaf8204feb497bb47aab977f04f5cea69b174e;p=pandora-kernel.git packet: fix race condition in packet_set_ring commit 84ac7260236a49c79eede91617700174c2c19b0c upstream. When packet_set_ring creates a ring buffer it will initialize a struct timer_list if the packet version is TPACKET_V3. This value can then be raced by a different thread calling setsockopt to set the version to TPACKET_V1 before packet_set_ring has finished. This leads to a use-after-free on a function pointer in the struct timer_list when the socket is closed as the previously initialized timer will not be deleted. The bug is fixed by taking lock_sock(sk) in packet_setsockopt when changing the packet version while also taking the lock at the start of packet_set_ring. Fixes: f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation.") Signed-off-by: Philip Pettersson Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- Reading git-diff-tree failed