From: Samanta Navarro <ferivoz@riseup.net>
Date: Sun, 8 Nov 2020 11:45:18 +0000 (+0000)
Subject: libblkid: allow a lot of mac partitions
X-Git-Tag: v2.36.1~11
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=b134be670d469643c4908cba612bf405396c4dfe;p=thirdparty%2Futil-linux.git

libblkid: allow a lot of mac partitions

If the map count is set to INT_MAX then the for loop does not stop
because its check is never false.

I have not found a correct upper limit. The other partition logics have
a maximum amount (exception is atari.c).

The loop itself wouldn't be endless. If the iteration reaches block 0
then the signature will be wrong. This means that map count = INT_MAX
case would fail even if such a setup would be correct on disk.

Signed-off-by: Samanta Navarro <ferivoz@riseup.net>
---

diff --git a/libblkid/src/partitions/mac.c b/libblkid/src/partitions/mac.c
index 4713d60427..2be91a6205 100644
--- a/libblkid/src/partitions/mac.c
+++ b/libblkid/src/partitions/mac.c
@@ -123,12 +123,12 @@ static int probe_mac_pt(blkid_probe pr,
 	ssf = block_size / 512;
 	nblks = be32_to_cpu(p->map_count);
 
-	for (i = 1; i <= nblks; ++i) {
+	for (i = 0; i < nblks; ++i) {
 		blkid_partition par;
 		uint32_t start;
 		uint32_t size;
 
-		p = (struct mac_partition *) get_mac_block(pr, block_size, i);
+		p = (struct mac_partition *) get_mac_block(pr, block_size, i + 1);
 		if (!p) {
 			if (errno)
 				return -errno;
@@ -141,7 +141,7 @@ static int probe_mac_pt(blkid_probe pr,
 			DBG(LOWPROBE, ul_debug(
 				"mac: inconsistent map_count in partition map, "
 				"entry[0]: %d, entry[%d]: %d",
-				nblks, i - 1,
+				nblks, i,
 				be32_to_cpu(p->map_count)));
 		}