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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Cc: Mikulas Patocka <mpatocka@redhat.com>,
	Mike Snitzer <snitzer@kernel.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.8 689/715] dm-integrity: fix a memory leak when rechecking the data
Date: Sun, 24 Mar 2024 18:34:28 -0400
Message-ID: <20240324223455.1342824-690-sashal@kernel.org>
In-Reply-To: <20240324223455.1342824-1-sashal@kernel.org>
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From: Mikulas Patocka <mpatocka@redhat.com>

[ Upstream commit 55e565c42dce81a4e49c13262d5bc4eb4c2e588a ]

Memory for the "checksums" pointer will leak if the data is rechecked
after checksum failure (because the associated kfree won't happen due
to 'goto skip_io').

Fix this by freeing the checksums memory before recheck, and just use
the "checksum_onstack" memory for storing checksum during recheck.

Fixes: c88f5e553fe3 ("dm-integrity: recheck the integrity tag after a failure")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/md/dm-integrity.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index 1fc901df84eb1..f194ce6bfacb5 100644
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -1848,12 +1848,12 @@ static void integrity_metadata(struct work_struct *w)
 			r = dm_integrity_rw_tag(ic, checksums, &dio->metadata_block, &dio->metadata_offset,
 						checksums_ptr - checksums, dio->op == REQ_OP_READ ? TAG_CMP : TAG_WRITE);
 			if (unlikely(r)) {
+				if (likely(checksums != checksums_onstack))
+					kfree(checksums);
 				if (r > 0) {
-					integrity_recheck(dio, checksums);
+					integrity_recheck(dio, checksums_onstack);
 					goto skip_io;
 				}
-				if (likely(checksums != checksums_onstack))
-					kfree(checksums);
 				goto error;
 			}
 
-- 
2.43.0