From: Theodore Ts'o <tytso@mit.edu>
Date: Tue, 10 Jul 2018 22:12:54 +0000 (-0400)
Subject: blkid: avoid FPE crash when probing a HFS+ superblock with a zero blocksize
X-Git-Tag: v1.44.4~35
X-Git-Url: https://git.whamcloud.com/?a=commitdiff_plain;h=e96393142ccd1da25ac1e2c9cebd7f20326f36c5;p=tools%2Fe2fsprogs.git

blkid: avoid FPE crash when probing a HFS+ superblock with a zero blocksize

This problem was reported by Adam Buchbinder.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---

diff --git a/lib/blkid/probe.c b/lib/blkid/probe.c
index 865d9aa..283ee0a 100644
--- a/lib/blkid/probe.c
+++ b/lib/blkid/probe.c
@@ -1184,6 +1184,8 @@ static int probe_hfs(struct blkid_probe *probe __BLKID_ATTR((unused)),
 }
 
 
+#define HFSPLUS_SECTOR_SIZE        512
+
 static int probe_hfsplus(struct blkid_probe *probe,
 			 struct blkid_magic *id,
 			 unsigned char *buf)
@@ -1247,6 +1249,9 @@ static int probe_hfsplus(struct blkid_probe *probe,
 	}
 
 	blocksize = blkid_be32(hfsplus->blocksize);
+	if (blocksize < HFSPLUS_SECTOR_SIZE)
+		return 1;
+
 	memcpy(extents, hfsplus->cat_file.extents, sizeof(extents));
 	cat_block = blkid_be32(extents[0].start_block);