# CVE-2022-50571: linux: In the Linux kernel, the following vulnerability has been resolved:  btrfs: call __btrfs_remove_free_space_cache_lock...

CVE-2022-50571 is fixed in linux on 1 platform, first by DEBIAN-CVE-2022-50571, released October 22, 2025. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2022-50571
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0020
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 22, 2025

## Description

In the Linux kernel, the following vulnerability has been resolved:  btrfs: call __btrfs_remove_free_space_cache_locked on cache load failure  Now that lockdep is staying enabled through our entire CI runs I started seeing the following stack in generic/475  ------------[ cut here ]------------ WARNING: CPU: 1 PID: 2171864 at fs/btrfs/discard.c:604 btrfs_discard_update_discardable+0x98/0xb0 CPU: 1 PID: 2171864 Comm: kworker/u4:0 Not tainted 5.19.0-rc8+ #789 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 Workqueue: btrfs-cache btrfs_work_helper RIP: 0010:btrfs_discard_update_discardable+0x98/0xb0 RSP: 0018:ffffb857c2f7bad0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8c85c605c200 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff86807c5b RDI: ffffffff868a831e RBP: ffff8c85c4c54000 R08: 0000000000000000 R09: 0000000000000000 R10: ffff8c85c66932f0 R11: 0000000000000001 R12: ffff8c85c3899010 R13: ffff8c85d5be4f40 R14: ffff8c85c4c54000 R15: ffff8c86114bfa80 FS:  0000000000000000(0000) GS:ffff8c863bd00000(0000) knlGS:0000000000000000 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2e7f168160 CR3: 000000010289a004 CR4: 0000000000370ee0 Call Trace:   __btrfs_remove_free_space_cache+0x27/0x30  load_free_space_cache+0xad2/0xaf0  caching_thread+0x40b/0x650  ? lock_release+0x137/0x2d0  btrfs_work_helper+0xf2/0x3e0  ? lock_is_held_type+0xe2/0x140  process_one_work+0x271/0x590  ? process_one_work+0x590/0x590  worker_thread+0x52/0x3b0  ? process_one_work+0x590/0x590  kthread+0xf0/0x120  ? kthread_complete_and_exit+0x20/0x20  ret_from_fork+0x1f/0x30  This is the code          ctl = block_group->free_space_ctl;         discard_ctl = &block_group->fs_info->discard_ctl;          lockdep_assert_held(&ctl->tree_lock);  We have a temporary free space ctl for loading the free space cache in order to avoid having allocations happening while we're loading the cache.  When we hit an error we free it all up, however this also calls btrfs_discard_update_discardable, which requires block_group->free_space_ctl->tree_lock to be held.  However this is our temporary ctl so this lock isn't held.  Fix this by calling __btrfs_remove_free_space_cache_locked instead so that we only clean up the entries and do not mess with the discardable stats.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.1.4-1 | [DEBIAN-CVE-2022-50571](https://patchblox.com/security/data/fix/linux/debian-cve-2022-50571.md) | Oct 22, 2025 |
| Linux | linux Debian 13.5 (trixie) | 6.1.4-1 | [DEBIAN-CVE-2022-50571](https://patchblox.com/security/data/fix/linux/debian-cve-2022-50571.md) | Oct 22, 2025 |
| Linux | linux Debian 14 | 6.1.4-1 | [DEBIAN-CVE-2022-50571](https://patchblox.com/security/data/fix/linux/debian-cve-2022-50571.md) | Oct 22, 2025 |

---

Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.