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authorCong Wang <xiyou.wangcong@gmail.com>2018-01-15 11:37:29 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-01-31 12:55:56 +0100
commit18717ee28ef5c0285ff969d1e9357529a8a9233f (patch)
tree3555c292a728e8be9e48b90168465d55c42e5801 /drivers/net/tun.c
parent1105145cb3d5eee496de1d55aaea160c78e1c5b5 (diff)
tun: fix a memory leak for tfile->tx_array
[ Upstream commit 4df0bfc79904b7169dc77dcce44598b1545721f9 ] tfile->tun could be detached before we close the tun fd, via tun_detach_all(), so it should not be used to check for tfile->tx_array. As Jason suggested, we probably have to clean it up unconditionally both in __tun_deatch() and tun_detach_all(), but this requires to check if it is initialized or not. Currently skb_array_cleanup() doesn't have such a check, so I check it in the caller and introduce a helper function, it is a bit ugly but we can always improve it in net-next. Reported-by: Dmitry Vyukov <dvyukov@google.com> Fixes: 1576d9860599 ("tun: switch to use skb array for tx") Cc: Jason Wang <jasowang@redhat.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net/tun.c')
-rw-r--r--drivers/net/tun.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 518cbfbc8b65..eb6dc28e5e52 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -525,6 +525,14 @@ static void tun_queue_purge(struct tun_file *tfile)
skb_queue_purge(&tfile->sk.sk_error_queue);
}
+static void tun_cleanup_tx_array(struct tun_file *tfile)
+{
+ if (tfile->tx_array.ring.queue) {
+ skb_array_cleanup(&tfile->tx_array);
+ memset(&tfile->tx_array, 0, sizeof(tfile->tx_array));
+ }
+}
+
static void __tun_detach(struct tun_file *tfile, bool clean)
{
struct tun_file *ntfile;
@@ -566,8 +574,7 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
tun->dev->reg_state == NETREG_REGISTERED)
unregister_netdevice(tun->dev);
}
- if (tun)
- skb_array_cleanup(&tfile->tx_array);
+ tun_cleanup_tx_array(tfile);
sock_put(&tfile->sk);
}
}
@@ -606,11 +613,13 @@ static void tun_detach_all(struct net_device *dev)
/* Drop read queue */
tun_queue_purge(tfile);
sock_put(&tfile->sk);
+ tun_cleanup_tx_array(tfile);
}
list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
tun_enable_queue(tfile);
tun_queue_purge(tfile);
sock_put(&tfile->sk);
+ tun_cleanup_tx_array(tfile);
}
BUG_ON(tun->numdisabled != 0);
@@ -2363,6 +2372,8 @@ static int tun_chr_open(struct inode *inode, struct file * file)
sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
+ memset(&tfile->tx_array, 0, sizeof(tfile->tx_array));
+
return 0;
}