From 4e12fbca62be10b09503cecc7507757874043474 Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Thu, 2 Jun 2022 16:02:54 +0200
Subject: [PATCH] libblkid: (mac) make sure block size is large enough
 [fuzzing]

Reported-by: Thibault Guittet <tguittet@redhat.com>
Signed-off-by: Karel Zak <kzak@redhat.com>
---
 libblkid/src/partitions/mac.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libblkid/src/partitions/mac.c b/libblkid/src/partitions/mac.c
index 092d31d322..75a558b0a3 100644
--- a/libblkid/src/partitions/mac.c
+++ b/libblkid/src/partitions/mac.c
@@ -93,6 +93,8 @@ static int probe_mac_pt(blkid_probe pr,
 	}
 
 	block_size = be16_to_cpu(md->block_size);
+	if (block_size < sizeof(struct mac_partition))
+		goto nothing;
 
 	/* The partition map always begins at physical block 1,
 	 * the second block on the disk.
