From: Keith Busch <kbusch@kernel.org>
Date: Wed, 10 Dec 2025 10:43:46 +0000 (-0800)
Subject: blk-mq-dma: always initialize dma state
X-Git-Tag: v6.19-rc1~23^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a0750fae73c55112ea11a4867bee40f11e679405;p=thirdparty%2Flinux.git

blk-mq-dma: always initialize dma state

Ensure the dma state is initialized when we're not using the contiguous
iova, otherwise the caller may be using a stale state from a previous
request that could use the coalesed iova allocation.

Fixes: 2f6b2565d43cdb5 ("block: accumulate memory segment gaps per bio")
Reported-by: Sebastian Ott <sebott@redhat.com>
Tested-by: Sebastian Ott <sebott@redhat.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/block/blk-mq-dma.c b/block/blk-mq-dma.c
index e9108ccaf4b0..6dc7a3c23ac8 100644
--- a/block/blk-mq-dma.c
+++ b/block/blk-mq-dma.c
@@ -199,6 +199,7 @@ static bool blk_dma_map_iter_start(struct request *req, struct device *dma_dev,
 	if (blk_can_dma_map_iova(req, dma_dev) &&
 	    dma_iova_try_alloc(dma_dev, state, vec.paddr, total_len))
 		return blk_rq_dma_map_iova(req, dma_dev, state, iter, &vec);
+	memset(state, 0, sizeof(*state));
 	return blk_dma_map_direct(req, dma_dev, iter, &vec);
 }