| From | Greg Kroah-Hartman <> | Subject | [ 76/82] tun: dont zeroize sock->file on detach | Date | Mon, 13 Aug 2012 13:19:52 -0700 |
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From: Greg KH <gregkh@linuxfoundation.org>
3.5-stable review patch. If anyone has any objections, please let me know.
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From: Stanislav Kinsbursky <skinsbursky@parallels.com>
commit 66d1b9263a371abd15806c53f486f0645ef31a8f upstream.
This is a fix for bug, introduced in 3.4 kernel by commit 1ab5ecb90cb6a3df1476e052f76a6e8f6511cb3d ("tun: don't hold network namespace by tun sockets"), which, among other things, replaced simple sock_put() by sk_release_kernel(). Below is sequence, which leads to oops for non-persistent devices:
tun_chr_close() tun_detach() <== tun->socket.file = NULL tun_free_netdev() sk_release_sock() sock_release(sock->file == NULL) iput(SOCK_INODE(sock)) <== dereference on NULL pointer
This patch just removes zeroing of socket's file from __tun_detach(). sock_release() will do this.
Reported-by: Ruan Zhijie <ruanzhijie@hotmail.com> Tested-by: Ruan Zhijie <ruanzhijie@hotmail.com> Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/net/tun.c | 1 - 1 file changed, 1 deletion(-)
--- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -185,7 +185,6 @@ static void __tun_detach(struct tun_stru netif_tx_lock_bh(tun->dev); netif_carrier_off(tun->dev); tun->tfile = NULL; - tun->socket.file = NULL; netif_tx_unlock_bh(tun->dev); /* Drop read queue */
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