diff options
| author | Amit Shah <amit.shah@redhat.com> | 2011-03-04 14:04:33 +1030 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-06 10:44:13 -0800 |
| commit | d7a62cd0332115d4c7c4689abea0d889a30d8349 (patch) | |
| tree | ced474d2ff1959576ac55f760bbafbe1073af11a /drivers | |
| parent | fb62c00a6d8942775abc23d1621db1252e2d93d1 (diff) | |
| download | lwn-d7a62cd0332115d4c7c4689abea0d889a30d8349.tar.gz lwn-d7a62cd0332115d4c7c4689abea0d889a30d8349.zip | |
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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/char/virtio_console.c | 8 |
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))) { kfree(buf); port->outvq_full = false; |