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authorJason Wang <jasowang@redhat.com>2013-01-11 16:59:34 +0000
committerDavid S. Miller <davem@davemloft.net>2013-01-11 19:42:02 -0800
commitdd38bd853082355641d0034aaf368e13ef2438f8 (patch)
treed30449d71cc6c1cbe9d5cc412c2046f4c1527c43 /drivers/net/tun.c
parent7c0c3b1a8a175437991ccc898ed66ec5e4a96208 (diff)
downloadlinux-dd38bd853082355641d0034aaf368e13ef2438f8.tar.bz2
tuntap: fix leaking reference count
Reference count leaking of both module and sock were found: - When a detached file were closed, its sock refcnt from device were not released, solving this by add the sock_put(). - The module were hold or drop unconditionally in TUNSETPERSIST, which means we if we set the persist flag for N times, we need unset it for another N times. Solving this by only hold or drop an reference when there's a flag change and also drop the reference count when the persist device is deleted. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/tun.c')
-rw-r--r--drivers/net/tun.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index a36b56f0940b..af372d0957fe 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -428,8 +428,10 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
/* Drop read queue */
skb_queue_purge(&tfile->sk.sk_receive_queue);
tun_set_real_num_queues(tun);
- } else if (tfile->detached && clean)
+ } else if (tfile->detached && clean) {
tun = tun_enable_queue(tfile);
+ sock_put(&tfile->sk);
+ }
if (clean) {
if (tun && tun->numqueues == 0 && tun->numdisabled == 0 &&
@@ -478,6 +480,9 @@ static void tun_detach_all(struct net_device *dev)
sock_put(&tfile->sk);
}
BUG_ON(tun->numdisabled != 0);
+
+ if (tun->flags & TUN_PERSIST)
+ module_put(THIS_MODULE);
}
static int tun_attach(struct tun_struct *tun, struct file *file)
@@ -1874,10 +1879,11 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
/* Disable/Enable persist mode. Keep an extra reference to the
* module to prevent the module being unprobed.
*/
- if (arg) {
+ if (arg && !(tun->flags & TUN_PERSIST)) {
tun->flags |= TUN_PERSIST;
__module_get(THIS_MODULE);
- } else {
+ }
+ if (!arg && (tun->flags & TUN_PERSIST)) {
tun->flags &= ~TUN_PERSIST;
module_put(THIS_MODULE);
}