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authorWANG Cong <xiyou.wangcong@gmail.com>2017-04-12 12:32:13 -0700
committerDavid S. Miller <davem@davemloft.net>2017-04-17 12:46:50 -0400
commit1215e51edad1272e669172b26aa12aac94810c7f (patch)
tree273156966c9fb351ee4181712ebbcfc576495258 /net/ipv4/raw.c
parent271a8b428f8361f3ad4c599835ccd34dd458b212 (diff)
downloadlinux-1215e51edad1272e669172b26aa12aac94810c7f.tar.bz2
ipv4: fix a deadlock in ip_ra_control
Similar to commit 87e9f0315952 ("ipv4: fix a potential deadlock in mcast getsockopt() path"), there is a deadlock scenario for IP_ROUTER_ALERT too: CPU0 CPU1 ---- ---- lock(rtnl_mutex); lock(sk_lock-AF_INET); lock(rtnl_mutex); lock(sk_lock-AF_INET); Fix this by always locking RTNL first on all setsockopt() paths. Note, after this patch ip_ra_lock is no longer needed either. Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/raw.c')
-rw-r--r--net/ipv4/raw.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 8119e1f66e03..9d943974de2b 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -682,7 +682,9 @@ static void raw_close(struct sock *sk, long timeout)
/*
* Raw sockets may have direct kernel references. Kill them.
*/
+ rtnl_lock();
ip_ra_control(sk, 0, NULL);
+ rtnl_unlock();
sk_common_release(sk);
}