Forwarded: [PATCH] dm cache: fix divide error in too_many_discard_blocks

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Subject: [PATCH] dm cache: fix divide error in too_many_discard_blocks
Author: drifabdelmalekmohamedsaid@gmail.com

#syz test

Signed-off-by: Drif Abdelmalek Mohamed Said <drifabdelmalekmohamedsaid@gmail.com>
---
 drivers/md/dm-cache-target.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 1a5072425c4a..408bc743a141 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -2383,6 +2383,8 @@ static int create_cache_policy(struct cache *cache, struct cache_args *ca,
 static bool too_many_discard_blocks(sector_t discard_block_size,
 				    sector_t origin_size)
 {
+	if (discard_block_size > U32 / 2)
+		return false;
 	(void) sector_div(origin_size, discard_block_size);
 
 	return origin_size > MAX_DISCARD_BLOCKS;
-- 
2.47.3