[PATCH 1/5] erofs-utils: fix delta[1] out-of-bound of compact indexes

[Gao Xiang]

delta[1] should not exceed (1 << lclusterbits) - 1, usually 4095
blocks, which means a single compressed extent which isn't less
than 16MiB could trigger this issue (it very rare happens).

Fixes: 76b822726ff8 ("erofs-utils: introduce compacted compression indexes")
Signed-off-by: Gao Xiang <hsiangkao at linux.alibaba.com>
---
 lib/compress.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/compress.c b/lib/compress.c
index 65c6f90..f38c795 100644
--- a/lib/compress.c
+++ b/lib/compress.c
@@ -627,7 +627,8 @@ static void *write_compacted_indexes(u8 *out,
 				blkaddr += cblks;
 				*dummy_head = false;
 			} else if (i + 1 == vcnt) {
-				offset = cv[i].u.delta[1];
+				offset = min_t(u16, cv[i].u.delta[1],
+						(1 << logical_clusterbits) - 1);
 			} else {
 				offset = cv[i].u.delta[0];
 			}
-- 
2.24.4