Summary
In the Linux kernel, the following vulnerability has been resolved: btrfs: call...
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.
Impact
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Frequently Asked Questions
- What is CVE-2022-50571? CVE-2022-50571 is a unknown-severity security vulnerability. No fixed version is listed yet.
- Is there a fix for CVE-2022-50571? No fixed version is listed for CVE-2022-50571 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2022-50571 exploitable, and should I be worried? Whether CVE-2022-50571 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2022-50571 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.