[RFC 1/6] block: refuse a dma-buf bio that carries a crypto context

[Mengmeng Zhao <mengmeng.zhao@linux.dev>]

From: Mengmeng Zhao <zhaomengmeng@kylinos.cn>

A dma-buf bio has no pages for the crypto layer to walk: the
software fallback would read the map as bio_vecs.  Refuse it in
blk_mq_submit_bio() before it can reach that path.

Signed-off-by: Mengmeng Zhao <zhaomengmeng@kylinos.cn>
Signed-off-by: Li Wang <liwang@kylinos.cn>
---
 block/blk-mq.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index be5671966787..f0d978b1724f 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3138,8 +3138,10 @@ void blk_mq_submit_bio(struct bio *bio)
 		goto queue_exit;
 	}
 
+	/* a dma-buf bio has no pages for integrity work or contents crypto */
 	if (unlikely(op_is_dmabuf(bio->bi_opf) &&
-		bdev_has_integrity_csum(bio->bi_bdev))) {
+	    (bdev_has_integrity_csum(bio->bi_bdev) ||
+	     bio_has_crypt_ctx(bio)))) {
 		bio_endio_status(bio, BLK_STS_NOTSUPP);
 		goto queue_exit;
 	}
-- 
2.43.0