lkml.org 
[lkml]   [2018]   [Jan]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.9 54/66] tun: fix a memory leak for tfile->tx_array
Date
4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Cong Wang <xiyou.wangcong@gmail.com>


[ 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>
---
drivers/net/tun.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)

--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -525,6 +525,14 @@ 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;
@@ -566,8 +574,7 @@ 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);
}
}
@@ -606,11 +613,13 @@ 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);

@@ -2363,6 +2372,8 @@ 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;
}


\
 
 \ /
  Last update: 2018-01-29 22:10    [W:0.418 / U:2.160 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site