From: Samanta Navarro <ferivoz@riseup.net>
Date: Tue, 10 Nov 2020 10:48:04 +0000 (+0100)
Subject: libblkid: limit amount of parsed partitions
X-Git-Tag: v2.37-rc1~386^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c70b4f2a5b99876d230b8f4f413c3bb3ee6647f1;p=thirdparty%2Futil-linux.git

libblkid: limit amount of parsed partitions

The linux kernel does not support more than 256 partitions
(DISK_MAX_PARTS). The atari and mac block devices have no such limits.

Use dos logical partition limit for atari as well (100).
Use the kernel limit for mac (256).

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

diff --git a/libblkid/src/partitions/atari.c b/libblkid/src/partitions/atari.c
index 3f9f4df53a..314f04763f 100644
--- a/libblkid/src/partitions/atari.c
+++ b/libblkid/src/partitions/atari.c
@@ -141,12 +141,16 @@ static int parse_extended(blkid_probe pr, blkid_partlist ls,
 	blkid_parttable tab, struct atari_part_def *part)
 {
 	uint32_t x0start, xstart;
-	unsigned i = 0;
+	unsigned ct = 0, i = 0;
 	int rc;
 
 	x0start = xstart = be32_to_cpu(part->start);
 	while (1) {
 		struct atari_rootsector *xrs;
+
+		if (++ct > 100)
+			break;
+
 		xrs = (struct atari_rootsector *) blkid_probe_get_sector(pr, xstart);
 		if (!xrs) {
 			if (errno)
diff --git a/libblkid/src/partitions/mac.c b/libblkid/src/partitions/mac.c
index 2be91a6205..092d31d322 100644
--- a/libblkid/src/partitions/mac.c
+++ b/libblkid/src/partitions/mac.c
@@ -79,7 +79,7 @@ static int probe_mac_pt(blkid_probe pr,
 	blkid_partlist ls;
 	uint16_t block_size;
 	uint16_t ssf;	/* sector size fragment */
-	uint32_t nblks, i;
+	uint32_t nblks, nprts, i;
 
 
 	/* The driver descriptor record is always located at physical block 0,
@@ -122,8 +122,15 @@ static int probe_mac_pt(blkid_probe pr,
 
 	ssf = block_size / 512;
 	nblks = be32_to_cpu(p->map_count);
-
-	for (i = 0; i < nblks; ++i) {
+	if (nblks > 256) {
+		nprts = 256;
+		DBG(LOWPROBE, ul_debug(
+			"mac: map_count too large, entry[0]: %u, "
+			"enforcing limit of %u", nblks, nprts));
+	} else
+		nprts = nblks;
+
+	for (i = 0; i < nprts; ++i) {
 		blkid_partition par;
 		uint32_t start;
 		uint32_t size;
@@ -140,7 +147,7 @@ static int probe_mac_pt(blkid_probe pr,
 		if (be32_to_cpu(p->map_count) != nblks) {
 			DBG(LOWPROBE, ul_debug(
 				"mac: inconsistent map_count in partition map, "
-				"entry[0]: %d, entry[%d]: %d",
+				"entry[0]: %u, entry[%u]: %u",
 				nblks, i,
 				be32_to_cpu(p->map_count)));
 		}