redonkable
/
remarkable-linux
1
0
Fork 0
Code Releases Activity

net: possible use after free in dst_release 

dst_release should not access dst->flags after decrementing
__refcnt to 0. The dst_entry may be in dst_busy_list and
dst_gc_task may dst_destroy it before dst_release gets a chance
to access dst->flags.

Fixes: d69bbf88c8 ("net: fix a race in dst_release()")
Fixes: 27b75c95f1 ("net: avoid RCU for NOCACHE dst")
Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
steinar/wifi_calib_4_9_kernel
Francesco Ruggeri 2016-01-06 00:18:48 -08:00 committed by David S. Miller
parent 73c20a8b72
commit 07a5d38453
1 changed files with 2 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
net/core/dst.c
View File

@ -301,12 +301,13 @@ void dst_release(struct dst_entry *dst)
{
if (dst) {
int newrefcnt;
unsigned short nocache = dst->flags & DST_NOCACHE;
newrefcnt = atomic_dec_return(&dst->__refcnt);
if (unlikely(newrefcnt < 0))
net_warn_ratelimited("%s: dst:%p refcnt:%d\n",
__func__, dst, newrefcnt);
if (!newrefcnt && unlikely(dst->flags & DST_NOCACHE))
if (!newrefcnt && unlikely(nocache))
call_rcu(&dst->rcu_head, dst_destroy_rcu);
}
}