4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Cong Wang <xiyou.wangcong@xxxxxxxxx>
[ 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@xxxxxxxxxx>
Fixes: 1576d9860599 ("tun: switch to use skb array for tx")
Cc: Jason Wang <jasowang@xxxxxxxxxx>
Signed-off-by: Cong Wang <xiyou.wangcong@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/tun.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -534,6 +534,14 @@ static void tun_queue_purge(struct tun_f
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;
@@ -575,8 +583,7 @@ static void __tun_detach(struct tun_file
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);
}
}
@@ -616,11 +623,13 @@ static void tun_detach_all(struct net_de
/* 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);
@@ -2624,6 +2633,8 @@ static int tun_chr_open(struct inode *in
sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
+ memset(&tfile->tx_array, 0, sizeof(tfile->tx_array));
+
return 0;
}