CVE-2023-52897: btrfs: qgroup: do not warn on record without old_roots populated

Description

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:

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

[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 leav...

Classification

CVE ID: CVE-2023-52897

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 11.48% (scored less or equal to compared to others)

EPSS Date: 2025-02-04 (when was this score calculated)

References

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

Timeline