diff options
| author | Francesco Ruggeri <fruggeri@aristanetworks.com> | 2016-01-06 11:18:48 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-01-06 23:00:27 +0300 |
| commit | 07a5d38453599052aff0877b16bb9c1585f08609 (patch) | |
| tree | 2e548a87ab4e08e97da4aabb6387f63d2cf06a98 | |
| parent | 73c20a8b7245273125cfe92c4b46e6fdb568a801 (diff) | |
| download | linux-07a5d38453599052aff0877b16bb9c1585f08609.tar.xz | |
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: d69bbf88c8d0 ("net: fix a race in dst_release()")
Fixes: 27b75c95f10d ("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>
| -rw-r--r-- | net/core/dst.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/core/dst.c b/net/core/dst.c index e6dc77252fe9..a1656e3b8d72 100644 --- a/net/core/dst.c +++ b/net/core/dst.c @@ -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); } } |