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| author | Eric Dumazet <edumazet@google.com> | 2015-11-09 17:51:23 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-11-09 21:55:48 -0500 |
| commit | d69bbf88c8d0b367cf3e3a052f6daadf630ee566 (patch) | |
| tree | 32b81467f642ab7a2b6d0b20b2a935eb85bae712 /net/core/dst.c | |
| parent | 8c94ddbc139bf8511d79153a81191b07f8e03eb4 (diff) | |
| download | linux-d69bbf88c8d0b367cf3e3a052f6daadf630ee566.tar.bz2 | |
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>
Diffstat (limited to 'net/core/dst.c')
| -rw-r--r-- | net/core/dst.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/dst.c b/net/core/dst.c index 2a1818065e12..e6dc77252fe9 100644 --- a/net/core/dst.c +++ b/net/core/dst.c @@ -306,7 +306,7 @@ void dst_release(struct dst_entry *dst) if (unlikely(newrefcnt < 0)) net_warn_ratelimited("%s: dst:%p refcnt:%d\n", __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); } } |