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* [PATCH] virtio-blk: fix implicit overflow on virtio_max_dma_size
@ 2023-09-04  6:10 zhenwei pi via Virtualization
  2023-10-19  9:43 ` PING: " zhenwei pi via Virtualization
  0 siblings, 1 reply; 4+ messages in thread
From: zhenwei pi via Virtualization @ 2023-09-04  6:10 UTC (permalink / raw)
  To: mst, jasowang, axboe; +Cc: xuanzhuo, linux-kernel, zhenwei pi, virtualization

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@bytedance.com>
---
 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 1fe011676d07..4a4b9bad551e 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. */
-- 
2.34.1

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end of thread, other threads:[~2023-10-20  2:28 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-09-04  6:10 [PATCH] virtio-blk: fix implicit overflow on virtio_max_dma_size zhenwei pi via Virtualization
2023-10-19  9:43 ` PING: " zhenwei pi via Virtualization
2023-10-19  9:52   ` Michael S. Tsirkin
2023-10-20  2:23     ` zhenwei pi via Virtualization

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