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tun: fix a memory leak for tfile->tx_array

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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>
This commit is contained in:
Cong Wang 2018-01-15 11:37:29 -08:00 committed by David S. Miller
parent 8cbab92dff
commit 4df0bfc799
1 changed files with 13 additions and 2 deletions
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15
drivers/net/tun.c
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@ -611,6 +611,14 @@ 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;
@ -657,8 +665,7 @@ 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);
}
}
@ -700,11 +707,13 @@ 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);
@ -2851,6 +2860,8 @@ 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;
}