Re: [PATCH] virtio_blk: Fix signedness bug in virtblk_prep_rq()
From: Stefano Garzarella
Date: Mon Oct 24 2022 - 16:55:47 EST
On Fri, Oct 21, 2022 at 05:41:26PM -0300, Rafael Mendonca wrote:
The virtblk_map_data() function returns negative error codes, however, the
'nents' field of vbr->sg_table is an unsigned int, which causes the error
handling not to work correctly.
Fixes: 0e9911fa768f ("virtio-blk: support mq_ops->queue_rqs()")
Signed-off-by: Rafael Mendonca <rafaelmendsr@xxxxxxxxx>
---
drivers/block/virtio_blk.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
Good catch!
Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 19da5defd734..291f705e61a8 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -321,16 +321,18 @@ static blk_status_t virtblk_prep_rq(struct blk_mq_hw_ctx *hctx,
struct virtblk_req *vbr)
{
blk_status_t status;
+ int num;
status = virtblk_setup_cmd(vblk->vdev, req, vbr);
if (unlikely(status))
return status;
- vbr->sg_table.nents = virtblk_map_data(hctx, req, vbr);
- if (unlikely(vbr->sg_table.nents < 0)) {
+ num = virtblk_map_data(hctx, req, vbr);
+ if (unlikely(num < 0)) {
virtblk_cleanup_cmd(req);
return BLK_STS_RESOURCE;
}
+ vbr->sg_table.nents = num;
blk_mq_start_request(req);
--
2.34.1