virtio-blk: Fix use after free in error case

virtio_blk_req_complete frees the request, so we can't access it any more when
calling bdrv_mon_event. Use the pointer that was copied earlier.

Signed-off-by: Kevin Wolf <[email protected]>
Signed-off-by: Luiz Capitulino <[email protected]>

diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
index 99158408873b5a7b9e3f14d45c6d50782b7e56bb..01d77b8672da6c3ba7741e271830387b816b8fe0 100644 (file)
--- a/hw/virtio-blk.c
+++ b/hw/virtio-blk.c
@@ -65,7 +65,7 @@ static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error,
     VirtIOBlock *s = req->dev;
 
     if (action == BLOCK_ERR_IGNORE) {
-        bdrv_mon_event(req->dev->bs, BDRV_ACTION_IGNORE, is_read);
+        bdrv_mon_event(s->bs, BDRV_ACTION_IGNORE, is_read);
         return 0;
     }
 
@@ -73,11 +73,11 @@ static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error,
             || action == BLOCK_ERR_STOP_ANY) {
         req->next = s->rq;
         s->rq = req;
-        bdrv_mon_event(req->dev->bs, BDRV_ACTION_STOP, is_read);
+        bdrv_mon_event(s->bs, BDRV_ACTION_STOP, is_read);
         vm_stop(0);
     } else {
         virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
-        bdrv_mon_event(req->dev->bs, BDRV_ACTION_REPORT, is_read);
+        bdrv_mon_event(s->bs, BDRV_ACTION_REPORT, is_read);
     }
 
     return 1;