linux-kernel - [PATCH] ocfs2: Fix shift-out-of-bounds UBSAN bug in ocfs2_verify

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]

Message-ID: <Zr9XJJlZ+RzkLK/M@hostname>
Date: Fri, 16 Aug 2024 14:41:56 +0100
From: qasdev <qasdev00@...il.com>
To: mark@...heh.com, jlbec@...lplan.org, joseph.qi@...ux.alibaba.com
Cc: ocfs2-devel@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: [PATCH] ocfs2: Fix shift-out-of-bounds UBSAN bug in
 ocfs2_verify_volume()

>From ad1ca2fd2ecf4eb7ec2c76fcbbf34639f0ad87ca Mon Sep 17 00:00:00 2001
From: Qasim Ijaz <qasdev00@...il.com>
Date: Fri, 16 Aug 2024 02:30:25 +0100
Subject: [PATCH] ocfs2: Fix shift-out-of-bounds UBSAN bug in
 ocfs2_verify_volume()

This patch addresses a shift-out-of-bounds error in the 
ocfs2_verify_volume() function, identified by UBSAN. The bug was triggered 
by an invalid s_clustersize_bits value (e.g., 1548), which caused the 
expression "1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits)" 
to exceed the limits of a 32-bit integer, 
leading to an out-of-bounds shift.

Reported-by: syzbot <syzbot+f3fff775402751ebb471@...kaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=f3fff775402751ebb471
Tested-by: syzbot <syzbot+f3fff775402751ebb471@...kaller.appspotmail.com>
Signed-off-by: Qasim Ijaz <qasdev00@...il.com>
---
 fs/ocfs2/super.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index afee70125ae3..1e43cdca7f40 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -2357,8 +2357,12 @@ static int ocfs2_verify_volume(struct ocfs2_dinode *di,
 			     (unsigned long long)bh->b_blocknr);
 		} else if (le32_to_cpu(di->id2.i_super.s_clustersize_bits) < 12 ||
 			    le32_to_cpu(di->id2.i_super.s_clustersize_bits) > 20) {
-			mlog(ML_ERROR, "bad cluster size found: %u\n",
-			     1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));
+			if (le32_to_cpu(di->id2.i_super.s_clustersize_bits) < 32)
+				mlog(ML_ERROR, "bad cluster size found: %u\n",
+				     1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));
+			else
+				mlog(ML_ERROR, "invalid cluster size bit value: %u\n",
+				     le32_to_cpu(di->id2.i_super.s_clustersize_bits));
 		} else if (!le64_to_cpu(di->id2.i_super.s_root_blkno)) {
 			mlog(ML_ERROR, "bad root_blkno: 0\n");
 		} else if (!le64_to_cpu(di->id2.i_super.s_system_dir_blkno)) {
-- 
2.30.2