From: Alexey Khoroshilov <khoroshilov@ispras.ru>
To: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Khoroshilov <khoroshilov@ispras.ru>,
Jason Wang <jasowang@redhat.com>,
Eric Dumazet <edumazet@google.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
ldv-project@linuxtesting.org
Subject: [PATCH] tun: fix mismatch in mutex lock-unlock in tun_get_user()
Date: Sat, 17 Feb 2018 01:11:55 +0300 [thread overview]
Message-ID: <1518819115-13507-1-git-send-email-khoroshilov@ispras.ru> (raw)
There is a single error path where tfile->napi_mutex is left unlocked.
It can lead to a deadlock.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
---
drivers/net/tun.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 81e6cc951e7f..0072a9832532 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1879,6 +1879,10 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
default:
this_cpu_inc(tun->pcpu_stats->rx_dropped);
kfree_skb(skb);
+ if (frags) {
+ tfile->napi.skb = NULL;
+ mutex_unlock(&tfile->napi_mutex);
+ }
return -EINVAL;
}
}
--
2.7.4
next reply other threads:[~2018-02-16 22:12 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-16 22:11 Alexey Khoroshilov [this message]
2018-02-16 22:44 ` [PATCH] tun: fix mismatch in mutex lock-unlock in tun_get_user() Eric Dumazet
2018-02-19 16:15 ` David Miller
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