nagai/kernel
3
0
Fork 0
forked from mirrors/linux
Code Pull requests Activity

net: fix a race in dst_release()

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

Otherwise an other cpu might already have freed the dst.

Fixes: 27b75c95f1 ("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>
This commit is contained in:
Eric Dumazet 2015-11-09 17:51:23 -08:00 committed by David S. Miller
parent 8c94ddbc13
commit d69bbf88c8
1 changed files with 1 additions and 1 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

2
net/core/dst.c
View file

@ -306,7 +306,7 @@ void dst_release(struct dst_entry *dst)
if (unlikely(newrefcnt < 0)) if (unlikely(newrefcnt < 0))
net_warn_ratelimited("%s: dst:%p refcnt:%d\n", net_warn_ratelimited("%s: dst:%p refcnt:%d\n",
__func__, dst, newrefcnt); __func__, dst, newrefcnt);
if (unlikely(dst->flags & DST_NOCACHE) && !newrefcnt) if (!newrefcnt && unlikely(dst->flags & DST_NOCACHE))
call_rcu(&dst->rcu_head, dst_destroy_rcu); call_rcu(&dst->rcu_head, dst_destroy_rcu);
} }
} }