[PATCH AUTOSEL 6.6 5/7] virtio-blk: fix implicit overflow on virtio_max_dma_size
From: Sasha Levin
Date: Sun Nov 12 2023 - 08:24:01 EST
From: zhenwei pi <pizhenwei@xxxxxxxxxxxxx>
[ Upstream commit fafb51a67fb883eb2dde352539df939a251851be ]
The following codes have an implicit conversion from size_t to u32:
(u32)max_size = (size_t)virtio_max_dma_size(vdev);
This may lead overflow, Ex (size_t)4G -> (u32)0. Once
virtio_max_dma_size() has a larger size than U32_MAX, use U32_MAX
instead.
Signed-off-by: zhenwei pi <pizhenwei@xxxxxxxxxxxxx>
Message-Id: <20230904061045.510460-1-pizhenwei@xxxxxxxxxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/block/virtio_blk.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 1fe011676d070..4a4b9bad551e8 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -1313,6 +1313,7 @@ static int virtblk_probe(struct virtio_device *vdev)
u16 min_io_size;
u8 physical_block_exp, alignment_offset;
unsigned int queue_depth;
+ size_t max_dma_size;
if (!vdev->config->get) {
dev_err(&vdev->dev, "%s failure: config access disabled\n",
@@ -1411,7 +1412,8 @@ static int virtblk_probe(struct virtio_device *vdev)
/* No real sector limit. */
blk_queue_max_hw_sectors(q, UINT_MAX);
- max_size = virtio_max_dma_size(vdev);
+ max_dma_size = virtio_max_dma_size(vdev);
+ max_size = max_dma_size > U32_MAX ? U32_MAX : max_dma_size;
/* Host can optionally specify maximum segment size and number of
* segments. */
--
2.42.0