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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Joe Thornber <ejt@redhat.com>,
        Mike Snitzer <snitzer@redhat.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 171/239] dm space map common: add bounds check to sm_ll_lookup_bitmap()
Date:   Mon, 24 Jan 2022 19:43:29 +0100
Message-Id: <20220124183948.538720161@linuxfoundation.org>
In-Reply-To: <20220124183943.102762895@linuxfoundation.org>
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From: Joe Thornber <ejt@redhat.com>

[ Upstream commit cba23ac158db7f3cd48a923d6861bee2eb7a2978 ]

Corrupted metadata could warrant returning error from sm_ll_lookup_bitmap().

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/md/persistent-data/dm-space-map-common.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/md/persistent-data/dm-space-map-common.c b/drivers/md/persistent-data/dm-space-map-common.c
index a284762e548e1..5115a27196038 100644
--- a/drivers/md/persistent-data/dm-space-map-common.c
+++ b/drivers/md/persistent-data/dm-space-map-common.c
@@ -279,6 +279,11 @@ int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
 	struct disk_index_entry ie_disk;
 	struct dm_block *blk;
 
+	if (b >= ll->nr_blocks) {
+		DMERR_LIMIT("metadata block out of bounds");
+		return -EINVAL;
+	}
+
 	b = do_div(index, ll->entries_per_block);
 	r = ll->load_ie(ll, index, &ie_disk);
 	if (r < 0)
-- 
2.34.1