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authorStanislav Kinsbursky <skinsbursky@parallels.com>2012-08-09 02:50:40 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-08-15 08:10:33 -0700
commitc6c0038af718e3c29d5369aa799ea120d8f67112 (patch)
treef4ed7a80f096ded173a693ff63b30a48959f5570
parent510f1d143b72225df068a31b2b105edaef5f2420 (diff)
tun: don't zeroize sock->file on detach
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>
-rw-r--r--drivers/net/tun.c1
1 files changed, 0 insertions, 1 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 8f13420dd31a..147b6284d7fa 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -185,7 +185,6 @@ 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 */