diff options
authorAmit Shah <amit.shah@redhat.com>2011-03-04 14:04:33 +1030
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-06 10:44:13 -0800
commitd7a62cd0332115d4c7c4689abea0d889a30d8349 (patch)
parentfb62c00a6d8942775abc23d1621db1252e2d93d1 (diff)
virtio: console: Don't access vqs if device was unplugged
If a virtio-console device gets unplugged while a port is open, a subsequent close() call on the port accesses vqs to free up buffers. This can lead to a crash. The buffers are already freed up as a result of the call to unplug_ports() from virtcons_remove(). The fix is to simply not access vq information if port->portdev is NULL. Reported-by: juzhang <juzhang@redhat.com> CC: stable@kernel.org Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 490393186338..84b164d1eb2b 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -388,6 +388,10 @@ static void discard_port_data(struct port *port)
unsigned int len;
int ret;
+ if (!port->portdev) {
+ /* Device has been unplugged. vqs are already gone. */
+ return;
+ }
vq = port->in_vq;
if (port->inbuf)
buf = port->inbuf;
@@ -470,6 +474,10 @@ static void reclaim_consumed_buffers(struct port *port)
void *buf;
unsigned int len;
+ if (!port->portdev) {
+ /* Device has been unplugged. vqs are already gone. */
+ return;
+ }
while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
port->outvq_full = false;