From 1f770c0a09da855a2b51af6d19de97fb955eca85 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Fri, 18 Sep 2015 19:16:50 +0800 Subject: netlink: Fix autobind race condition that leads to zero port ID The commit c0bb07df7d981e4091432754e30c9c720e2c0c78 ("netlink: Reset portid after netlink_insert failure") introduced a race condition where if two threads try to autobind the same socket one of them may end up with a zero port ID. This led to kernel deadlocks that were observed by multiple people. This patch reverts that commit and instead fixes it by introducing a separte rhash_portid variable so that the real portid is only set after the socket has been successfully hashed. Fixes: c0bb07df7d98 ("netlink: Reset portid after netlink_insert failure") Reported-by: Tejun Heo Reported-by: Linus Torvalds Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/netlink/af_netlink.h | 1 + 1 file changed, 1 insertion(+) (limited to 'net/netlink/af_netlink.h') diff --git a/net/netlink/af_netlink.h b/net/netlink/af_netlink.h index df9a06090db6..80b2b7526dfd 100644 --- a/net/netlink/af_netlink.h +++ b/net/netlink/af_netlink.h @@ -25,6 +25,7 @@ struct netlink_ring { struct netlink_sock { /* struct sock has to be the first member of netlink_sock */ struct sock sk; + u32 rhash_portid; u32 portid; u32 dst_portid; u32 dst_group; -- cgit v1.2.3