From 66d1b9263a371abd15806c53f486f0645ef31a8f Mon Sep 17 00:00:00 2001 From: Stanislav Kinsbursky Date: Thu, 9 Aug 2012 02:50:40 +0000 Subject: [PATCH] tun: don't zeroize sock->file on detach 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. Cc: stable@vger.kernel.org Reported-by: Ruan Zhijie Tested-by: Ruan Zhijie Acked-by: Al Viro Acked-by: Eric Dumazet Acked-by: Yuchung Cheng Signed-off-by: Stanislav Kinsbursky Signed-off-by: David S. Miller --- drivers/net/tun.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 926d4db5cb38..3a16d4fdaa05 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -187,7 +187,6 @@ static void __tun_detach(struct tun_struct *tun) 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 */ -- 2.39.5