* [PATCH net] tuntap: fix use after free during release
@ 2018-05-16 12:39 Jason Wang
2018-05-16 18:53 ` David Miller
0 siblings, 1 reply; 2+ messages in thread
From: Jason Wang @ 2018-05-16 12:39 UTC (permalink / raw)
To: netdev, linux-kernel; +Cc: xiyou.wangcong, avagin, mst, Jason Wang
After commit b196d88aba8a ("tun: fix use after free for ptr_ring") we
need clean up tx ring during release(). But unfortunately, it tries to
do the cleanup blindly after socket were destroyed which will lead
another use-after-free. Fix this by doing the cleanup before dropping
the last reference of the socket in __tun_detach().
Reported-by: Andrei Vagin <avagin@virtuozzo.com>
Acked-by: Andrei Vagin <avagin@virtuozzo.com>
Fixes: b196d88aba8a ("tun: fix use after free for ptr_ring")
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/tun.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 9fbbb32..d45ac37 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -729,6 +729,7 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
}
if (tun)
xdp_rxq_info_unreg(&tfile->xdp_rxq);
+ ptr_ring_cleanup(&tfile->tx_ring, tun_ptr_free);
sock_put(&tfile->sk);
}
}
@@ -3245,7 +3246,6 @@ static int tun_chr_close(struct inode *inode, struct file *file)
struct tun_file *tfile = file->private_data;
tun_detach(tfile, true);
- ptr_ring_cleanup(&tfile->tx_ring, tun_ptr_free);
return 0;
}
--
2.7.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH net] tuntap: fix use after free during release
2018-05-16 12:39 [PATCH net] tuntap: fix use after free during release Jason Wang
@ 2018-05-16 18:53 ` David Miller
0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2018-05-16 18:53 UTC (permalink / raw)
To: jasowang; +Cc: netdev, linux-kernel, xiyou.wangcong, avagin, mst
From: Jason Wang <jasowang@redhat.com>
Date: Wed, 16 May 2018 20:39:33 +0800
> After commit b196d88aba8a ("tun: fix use after free for ptr_ring") we
> need clean up tx ring during release(). But unfortunately, it tries to
> do the cleanup blindly after socket were destroyed which will lead
> another use-after-free. Fix this by doing the cleanup before dropping
> the last reference of the socket in __tun_detach().
>
> Reported-by: Andrei Vagin <avagin@virtuozzo.com>
> Acked-by: Andrei Vagin <avagin@virtuozzo.com>
> Fixes: b196d88aba8a ("tun: fix use after free for ptr_ring")
> Signed-off-by: Jason Wang <jasowang@redhat.com>
Applied and queued up for -stable.
^ permalink raw reply [flat|nested] 2+ messages in thread
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