From: Milan Broz <gmazyland@gmail.com>
Date: Fri, 31 Jul 2026 14:27:45 +0000 (+0200)
Subject: libblkid: befs: fix possible load of misaligned address
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=5f00ac15c9da815cb7ed5a6d461c4e2262f59955;p=thirdparty%2Futil-linux.git

libblkid: befs: fix possible load of misaligned address

The misaligned uint16_t loads can come only form a corrupt metadata.

Found by OSS-Fuzz by cryptsetup project fuzzers (issue 507641687).

Signed-off-by: Milan Broz <gmazyland@gmail.com>
---

diff --git a/libblkid/src/superblocks/befs.c b/libblkid/src/superblocks/befs.c
index a7a9d30a9..1e0550cb0 100644
--- a/libblkid/src/superblocks/befs.c
+++ b/libblkid/src/superblocks/befs.c
@@ -329,6 +329,10 @@ static int64_t get_key_value(blkid_probe pr, const struct befs_super_block *bs,
 		keylengths = (uint16_t *) ((uint8_t *) bn + keylengths_offset);
 		values = (int64_t *) ((uint8_t *) bn + values_offset);
 
+		 /* Misaligned offset comes only from corrupt metadata. */
+		if ((uintptr_t) keylengths % sizeof(*keylengths))
+			return -ENOENT; /* Corrupt? */
+
 		first = 0;
 		mid = 0;
 		last = all_key_count - 1;