From: Christoph Hellwig <hch@lst.de>
Date: Wed, 6 Apr 2011 18:28:34 +0000 (+0200)
Subject: virtio-blk: fail unaligned requests
X-Git-Url: https://repo.jachan.dev/qemu.git/commitdiff_plain/52c050236eaa4f0b5e1d160cd66dc18106445c4d

virtio-blk: fail unaligned requests

Like all block drivers virtio-blk should not allow small than block size
granularity access.  But given that the protocol specifies a
byte unit length field we currently accept such requests, which cause
qemu to abort() in lower layers.  Add checks to the main read and
write handlers to catch them early.

Reported-by: Conor Murphy <conor_murphy_virt@hotmail.com>
Tested-by: Conor Murphy <conor_murphy_virt@hotmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---

diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
index b14fb995e8..91e0394af9 100644
--- a/hw/virtio-blk.c
+++ b/hw/virtio-blk.c
@@ -290,6 +290,10 @@ static void virtio_blk_handle_write(VirtIOBlockReq *req, MultiReqBuffer *mrb)
         virtio_blk_rw_complete(req, -EIO);
         return;
     }
+    if (req->qiov.size % req->dev->conf->logical_block_size) {
+        virtio_blk_rw_complete(req, -EIO);
+        return;
+    }
 
     if (mrb->num_writes == 32) {
         virtio_submit_multiwrite(req->dev->bs, mrb);
@@ -317,6 +321,10 @@ static void virtio_blk_handle_read(VirtIOBlockReq *req)
         virtio_blk_rw_complete(req, -EIO);
         return;
     }
+    if (req->qiov.size % req->dev->conf->logical_block_size) {
+        virtio_blk_rw_complete(req, -EIO);
+        return;
+    }
 
     acb = bdrv_aio_readv(req->dev->bs, sector, &req->qiov,
                          req->qiov.size / BDRV_SECTOR_SIZE,