btrfs：qgroup：未填充 old_roots 时不发出记录警告（CVE-2023-52897）

CVE编号

CVE-2023-52897

利用情况

暂无

补丁情况

N/A

披露时间

2024-08-21

漏洞描述

In the Linux kernel, the following vulnerability has been resolved: btrfs: qgroup: do not warn on record without old_roots populated [BUG] There are some reports from the mailing list that since v6.1 kernel, the WARN_ON() inside btrfs_qgroup_account_extent() gets triggered during rescan: WARNING: CPU: 3 PID: 6424 at fs/btrfs/qgroup.c:2756 btrfs_qgroup_account_extents+0x1ae/0x260 [btrfs] CPU: 3 PID: 6424 Comm: snapperd Tainted: P OE 6.1.2-1-default #1 openSUSE Tumbleweed 05c7a1b1b61d5627475528f71f50444637b5aad7 RIP: 0010:btrfs_qgroup_account_extents+0x1ae/0x260 [btrfs] Call Trace: <TASK> btrfs_commit_transaction+0x30c/0xb40 [btrfs c39c9c546c241c593f03bd6d5f39ea1b676250f6] ? start_transaction+0xc3/0x5b0 [btrfs c39c9c546c241c593f03bd6d5f39ea1b676250f6] btrfs_qgroup_rescan+0x42/0xc0 [btrfs c39c9c546c241c593f03bd6d5f39ea1b676250f6] btrfs_ioctl+0x1ab9/0x25c0 [btrfs c39c9c546c241c593f03bd6d5f39ea1b676250f6] ? __rseq_handle_notify_resume+0xa9/0x4a0 ? mntput_no_expire+0x4a/0x240 ? __seccomp_filter+0x319/0x4d0 __x64_sys_ioctl+0x90/0xd0 do_syscall_64+0x5b/0x80 ? syscall_exit_to_user_mode+0x17/0x40 ? do_syscall_64+0x67/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fd9b790d9bf </TASK> [CAUSE] Since commit e15e9f43c7ca ("btrfs: introduce BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING to skip qgroup accounting"), if our qgroup is already in inconsistent state, we will no longer do the time-consuming backref walk. This can leave some qgroup records without a valid old_roots ulist. Normally this is fine, as btrfs_qgroup_account_extents() would also skip those records if we have NO_ACCOUNTING flag set. But there is a small window, if we have NO_ACCOUNTING flag set, and inserted some qgroup_record without a old_roots ulist, but then the user triggered a qgroup rescan. During btrfs_qgroup_rescan(), we firstly clear NO_ACCOUNTING flag, then commit current transaction. And since we have a qgroup_record with old_roots = NULL, we trigger the WARN_ON() during btrfs_qgroup_account_extents(). [FIX] Unfortunately due to the introduction of NO_ACCOUNTING flag, the assumption that every qgroup_record would have its old_roots populated is no longer correct. Fix the false alerts and drop the WARN_ON().

解决建议

建议您更新当前系统或软件至最新版，完成漏洞的修复。

参考链接
https://git.kernel.org/stable/c/75181406b4eafacc531ff2ee5fb032bd93317e2b
https://git.kernel.org/stable/c/bb2c2e62539f2b63c5e0beb51501d328260c7595

受影响软件情况

#	类型	厂商	产品	版本	影响面
1
	运行在以下环境
	系统	debian_11	linux	*		Up to (excluding) 5.10.223-1
	运行在以下环境
	系统	debian_12	linux	*		Up to (excluding) 6.1.8-1

CVSS3评分 N/A

• 攻击路径 N/A
• 攻击复杂度 N/A
• 权限要求 N/A
• 影响范围 N/A
• 用户交互 N/A
• 可用性 N/A
• 保密性 N/A
• 完整性 N/A

N/A

CWE-ID	漏洞类型

Exp相关链接

- avd.aliyun.com