linux-kernel - [PATCH 5.10.y] jfs: Fix shift-out-of-bounds in dbDiscardAG

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>] [day] [month] [year] [list]

Message-Id: <20250416015106.1714709-1-Zhi.Yang@eng.windriver.com>
Date: Wed, 16 Apr 2025 09:51:06 +0800
From: Zhi Yang <Zhi.Yang@....windriver.com>
To: stable@...r.kernel.org, peili.dev@...il.com
Cc: xiangyu.chen@...driver.com, zhe.he@...driver.com, shaggy@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 5.10.y] jfs: Fix shift-out-of-bounds in dbDiscardAG

From: Pei Li <peili.dev@...il.com>

commit 7063b80268e2593e58bee8a8d709c2f3ff93e2f2 upstream.

When searching for the next smaller log2 block, BLKSTOL2() returned 0,
causing shift exponent -1 to be negative.

This patch fixes the issue by exiting the loop directly when negative
shift is found.

Reported-by: syzbot+61be3359d2ee3467e7e4@...kaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=61be3359d2ee3467e7e4
Signed-off-by: Pei Li <peili.dev@...il.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@...cle.com>
Signed-off-by: Zhi Yang <Zhi.Yang@...driver.com>
Signed-off-by: He Zhe <zhe.he@...driver.com>
---
Build test passed.
---
 fs/jfs/jfs_dmap.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index ef220709c7f5..ce2b18337a20 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -1694,6 +1694,8 @@ s64 dbDiscardAG(struct inode *ip, int agno, s64 minlen)
 		} else if (rc == -ENOSPC) {
 			/* search for next smaller log2 block */
 			l2nb = BLKSTOL2(nblocks) - 1;
+			if (unlikely(l2nb < 0))
+				break;
 			nblocks = 1LL << l2nb;
 		} else {
 			/* Trim any already allocated blocks */
-- 
2.34.1