linux-kernel - [PATCH] udf: balloc: prevent integer overflow in udf_bitmap_free

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date: Mon, 10 Jun 2024 10:25:22 +0300
From: Roman Smirnov <r.smirnov@....ru>
To: Jan Kara <jack@...e.com>, <linux-kernel@...r.kernel.org>
CC: Roman Smirnov <r.smirnov@....ru>, Sergey Shtylyov <s.shtylyov@....ru>,
	<lvc-project@...uxtesting.org>
Subject: [PATCH] udf: balloc: prevent integer overflow in udf_bitmap_free_blocks()

An overflow may occur if the function is called with the last
block and an offset greater than zero. It is necessary to add
a check to avoid this.

Found by Linux Verification Center (linuxtesting.org) with Svace.

Signed-off-by: Roman Smirnov <r.smirnov@....ru>
---
 fs/udf/balloc.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/fs/udf/balloc.c b/fs/udf/balloc.c
index ab3ffc355949..cd83bbc7d890 100644
--- a/fs/udf/balloc.c
+++ b/fs/udf/balloc.c
@@ -151,6 +151,13 @@ static void udf_bitmap_free_blocks(struct super_block *sb,
 	block = bloc->logicalBlockNum + offset +
 		(sizeof(struct spaceBitmapDesc) << 3);
 
+	if (block < offset + (sizeof(struct spaceBitmapDesc) << 3)) {
+		udf_debug("integer overflow: %u + %u + %zu",
+			  bloc->logicalBlockNum, offset,
+			  sizeof(struct spaceBitmapDesc) << 3);
+		goto error_return;
+	}
+
 	do {
 		overflow = 0;
 		block_group = block >> (sb->s_blocksize_bits + 3);
-- 
2.34.1