[net] vhost_net: validate sock before trying to put its fd
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Message ID 1529557891-4828-1-git-send-email-jasowang@redhat.com
State New
Headers show

Commit Message

Jason Wang June 21, 2018, 5:11 a.m. UTC
Sock will be NULL if we pass -1 to vhost_net_set_backend(), but when
we meet errors during ubuf allocation, the code does not check for
NULL before calling sockfd_put(), this will lead NULL
dereferencing. Fixing by checking sock pointer before.

Fixes: bab632d69ee4 ("vhost: vhost TX zero-copy support")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/vhost/net.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

David Miller June 23, 2018, 1:24 a.m. UTC | #1
From: Jason Wang <jasowang@redhat.com>
Date: Thu, 21 Jun 2018 13:11:31 +0800

> Sock will be NULL if we pass -1 to vhost_net_set_backend(), but when
> we meet errors during ubuf allocation, the code does not check for
> NULL before calling sockfd_put(), this will lead NULL
> dereferencing. Fixing by checking sock pointer before.
> 
> Fixes: bab632d69ee4 ("vhost: vhost TX zero-copy support")
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>

Applied and queued up for -stable, thanks Jason.

Patch
diff mbox

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 986058a..b97a994 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -1208,7 +1208,8 @@  static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
 	if (ubufs)
 		vhost_net_ubuf_put_wait_and_free(ubufs);
 err_ubufs:
-	sockfd_put(sock);
+	if (sock)
+		sockfd_put(sock);
 err_vq:
 	mutex_unlock(&vq->mutex);
 err: