Subject: FAILED: patch "[PATCH] virtio_blk: Fix signedness bug in virtblk_prep_rq()" failed to apply to 6.0-stable tree
To:     rafaelmendsr@gmail.com, jasowang@redhat.com, mst@redhat.com,
        sgarzare@redhat.com, stefanha@redhat.com, suwan.kim027@gmail.com
Cc:     <stable@vger.kernel.org>
From:   <gregkh@linuxfoundation.org>
Date:   Tue, 10 Jan 2023 09:08:06 +0100
Message-ID: <1673338086125255@kroah.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=ANSI_X3.4-1968
Content-Transfer-Encoding: 8bit
Precedence: bulk


The patch below does not apply to the 6.0-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

Possible dependencies:

a26116c1e740 ("virtio_blk: Fix signedness bug in virtblk_prep_rq()")
258896fcc786 ("virtio-blk: use a helper to handle request queuing errors")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From a26116c1e74028914f281851488546c91cbae57d Mon Sep 17 00:00:00 2001
From: Rafael Mendonca <rafaelmendsr@gmail.com>
Date: Fri, 21 Oct 2022 17:41:26 -0300
Subject: [PATCH] virtio_blk: Fix signedness bug in virtblk_prep_rq()

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.

Cc: stable@vger.kernel.org
Fixes: 0e9911fa768f ("virtio-blk: support mq_ops->queue_rqs()")
Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Message-Id: <20221021204126.927603-1-rafaelmendsr@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Suwan Kim <suwan.kim027@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index dcbf86cd2155..6a77fa917428 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -334,14 +334,16 @@ 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))
 		return virtblk_fail_to_queue(req, -ENOMEM);
+	vbr->sg_table.nents = num;
 
 	blk_mq_start_request(req);