This is a note to let you know that I've just added the patch titled geneve: Fix races between socket add and release. to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: geneve-fix-races-between-socket-add-and-release.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Sat Jan 17 18:12:21 PST 2015 From: Jesse Gross <jesse@xxxxxxxxxx> Date: Tue, 16 Dec 2014 18:25:32 -0800 Subject: geneve: Fix races between socket add and release. From: Jesse Gross <jesse@xxxxxxxxxx> [ Upstream commit 12069401d895ff84076a50189ca842c0696b84b2 ] Currently, searching for a socket to add a reference to is not synchronized with deletion of sockets. This can result in use after free if there is another operation that is removing a socket at the same time. Solving this requires both holding the appropriate lock and checking the refcount to ensure that it has not already hit zero. Inspired by a related (but not exactly the same) issue in the VXLAN driver. Fixes: 0b5e8b8e ("net: Add Geneve tunneling protocol driver") CC: Andy Zhou <azhou@xxxxxxxxxx> Signed-off-by: Jesse Gross <jesse@xxxxxxxxxx> Acked-by: Thomas Graf <tgraf@xxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv4/geneve.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) --- a/net/ipv4/geneve.c +++ b/net/ipv4/geneve.c @@ -302,6 +302,7 @@ struct geneve_sock *geneve_sock_add(stru geneve_rcv_t *rcv, void *data, bool no_share, bool ipv6) { + struct geneve_net *gn = net_generic(net, geneve_net_id); struct geneve_sock *gs; gs = geneve_socket_create(net, port, rcv, data, ipv6); @@ -311,15 +312,15 @@ struct geneve_sock *geneve_sock_add(stru if (no_share) /* Return error if sharing is not allowed. */ return ERR_PTR(-EINVAL); + spin_lock(&gn->sock_lock); gs = geneve_find_sock(net, port); - if (gs) { - if (gs->rcv == rcv) - atomic_inc(&gs->refcnt); - else + if (gs && ((gs->rcv != rcv) || + !atomic_add_unless(&gs->refcnt, 1, 0))) gs = ERR_PTR(-EBUSY); - } else { + spin_unlock(&gn->sock_lock); + + if (!gs) gs = ERR_PTR(-EINVAL); - } return gs; } Patches currently in stable-queue which might be from jesse@xxxxxxxxxx are queue-3.18/net-generalize-ndo_gso_check-to-ndo_features_check.patch queue-3.18/geneve-remove-socket-and-offload-handlers-at-destruction.patch queue-3.18/geneve-fix-races-between-socket-add-and-release.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html