net: fix a race in dst_release()
authorEric Dumazet <edumazet@google.com>
Tue, 10 Nov 2015 01:51:23 +0000 (17:51 -0800)
committerDavid S. Miller <davem@davemloft.net>
Tue, 10 Nov 2015 02:55:48 +0000 (21:55 -0500)
commitd69bbf88c8d0b367cf3e3a052f6daadf630ee566
tree32b81467f642ab7a2b6d0b20b2a935eb85bae712
parent8c94ddbc139bf8511d79153a81191b07f8e03eb4
net: fix a race in dst_release()

Only cpu seeing dst refcount going to 0 can safely
dereference dst->flags.

Otherwise an other cpu might already have freed the dst.

Fixes: 27b75c95f10d ("net: avoid RCU for NOCACHE dst")
Reported-by: Greg Thelen <gthelen@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/core/dst.c