linux-kernel - Re: [syzbot] [ext4?] WARNING in ext4_xattr_inode_update

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20251103074641.4160652-1-lizhi.xu@windriver.com>
Date: Mon, 3 Nov 2025 15:46:41 +0800
From: Lizhi Xu <lizhi.xu@...driver.com>
To: <syzbot+76916a45d2294b551fd9@...kaller.appspotmail.com>
CC: <linux-kernel@...r.kernel.org>, <syzkaller-bugs@...glegroups.com>
Subject: Re: [syzbot] [ext4?] WARNING in ext4_xattr_inode_update_ref (2)

#syz test

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index ce7253b3f549..b7860b96e8bb 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1041,6 +1041,13 @@ static int ext4_xattr_inode_update_ref(handle_t *handle, struct inode *ea_inode,
 		goto out;
 	}
 	ref_count += ref_change;
+	if (overflows_type(ref_count, u64)) {
+		ext4_error_inode(ea_inode, __func__, __LINE__, 0,
+			"EA inode %lu ref overflows: ref_count=%lld ref_change=%d",
+			ea_inode->i_ino, ref_count, ref_change);
+		ret = -EFSCORRUPTED;
+		goto out;
+	}
 	ext4_xattr_inode_set_ref(ea_inode, ref_count);
 
 	if (ref_change > 0) {