btrfs: fix hang during unmount when stopping a space reclaim worker
In the Linux kernel, the following vulnerability has been resolved: btrfs: fix hang during unmount when stopping a space reclaim worker Often when running generic/562 from fstests we can hang during unmount, resulting in a trace like this: Sep 07 11:52:00 debian9 unknown: run fstests generic/562 at 2022-09-07 11:52:00 Sep 07 11:55:32 debian9 kernel: INFO: task umount:49438 blocked for more than 120 seconds. Sep 07 11:55:32 debian9 kernel: Not tainted 6.0.0-rc2-btrfs-next-122 #1 Sep 07 11:55:32 debian9 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Sep 07 11:55:32 debian9 kernel: task:umount state:D stack: 0 pid:49438 ppid: 25683 flags:0x00004000 Sep 07 11:55:32 debian9 kernel: Call Trace: Sep 07 11:55:32 debian9 kernel: <TASK> Sep 07 11:55:32 debian9 kernel: __schedule+0x3c8/0xec0 Sep 07 11:55:32 debian9 kernel: ? rcu_read_lock_sched_held+0x12/0x70 Sep 07 11:55:32 debian9 kernel: schedule+0x5d/0xf0 Sep 07 11:55:32 debian9 kernel: schedule_timeout+0xf1/0x130 Sep 07 11:55:32 debian9 kernel: ? lock_release+0x224/0x4a0 Sep 07 11:55:32 debian9 kernel: ? lock_acquired+0x1a0/0x420 Sep 07 11:55:32 debian9 kernel: ? trace_hardirqs_on+0x2c/0xd0 Sep 07 11:55:32 debian9 kernel: __wait_for_common+0xac/0x200 Sep 07 11:55:32 debian9 kernel: ? usleep_range_state+0xb0/0xb0 Sep 07 11:55:32 debian9 kernel: __flush_work+0x26d/0x530 Sep 07 11:55:32 debian9 kernel: ? flush_workqueue_prep_pwqs+0x140/0x140 Sep 07 11:55:32 debian9 kernel: ? trace_clock_local+0xc/0x30 Sep 07 11:55:32 debian9 kernel: __cancel_work_timer+0x11f/0x1b0 Sep 07 11:55:32 debian9 kernel: ? close_ctree+0x12b/0x5b3 [btrfs] Sep 07 11:55:32 debian9 kernel: ? __trace_bputs+0x10b/0x170 Sep 07 11:55:32 debian9 kernel: close_ctree+0x152/0x5b3 [btrfs] Sep 07 11:55:32 debian9 kernel: ? evict_inodes+0x166/0x1c0 Sep 07 11:55:32 debian9 kernel: generic_shutdown_super+0x71/0x120 Sep 07 11:55:32 debian9 kernel: kill_anon_super+0x14/0x30 Sep 07 11:55:32 debian9 kernel: btrfs_kill_super+0x12/0x20 [btrfs] Sep 07 11:55:32 debian9 kernel: deactivate_locked_super+0x2e/0xa0 Sep 07 11:55:32 debian9 kernel: cleanup_mnt+0x100/0x160 Sep 07 11:55:32 debian9 kernel: task_work_run+0x59/0xa0 Sep 07 11:55:32 debian9 kernel: exit_to_user_mode_prepare+0x1a6/0x1b0 Sep 07 11:55:32 debian9 kernel: syscall_exit_to_user_mode+0x16/0x40 Sep 07 11:55:32 debian9 kernel: do_syscall_64+0x48/0x90 Sep 07 11:55:32 debian9 kernel: entry_SYSCALL_64_after_hwframe+0x63/0xcd Sep 07 11:55:32 debian9 kernel: RIP: 0033:0x7fcde59a57a7 Sep 07 11:55:32 debian9 kernel: RSP: 002b:00007ffe914217c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 Sep 07 11:55:32 debian9 kernel: RAX: 0000000000000000 RBX: 00007fcde5ae8264 RCX: 00007fcde59a57a7 Sep 07 11:55:32 debian9 kernel: RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000055b57556cdd0 Sep 07 11:55:32 debian9 kernel: RBP: 000055b57556cba0 R08: 0000000000000000 R09: 00007ffe91420570 Sep 07 11:55:32 debian9 kernel: R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 Sep 07 11:55:32 debian9 kernel: R13: 000055b57556cdd0 R14: 000055b57556ccb8 R15: 0000000000000000 Sep 07 11:55:32 debian9 kernel: </TASK> What happens is the following: 1) The cleaner kthread tries to start a transaction to delete an unused block group, but the metadata reservation can not be satisfied right away, so a reservation ticket is created and it starts the async metadata reclaim task (fs_info->async_reclaim_work); 2) Writeback for all the filler inodes with an i_size of 2K starts (generic/562 creates a lot of 2K files with the goal of filling metadata space). We try to create an inline extent for them, but we fail when trying to insert the inline extent with -ENOSPC (at cow_file_range_inline()) - since this is not critical, we fallback to non-inline mode (back to cow_file_range()), reserve extents ---truncated---
- Published
- Apr 28, 2024
- Updated
- Jun 17, 2026
- EPSS
- 0.2% · 13th percentile
- CWE
- —
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Report tools
Action score
22
Monitor
Low priority for now.
- CVSS
- 22 / 40 · 5.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| linux | linux kernel | cpe:2.3:o:linux:linux_kernel |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- linux linux kernel4.14.120 and later · before 4.15
- linux linux kernel4.19.12 and later · before 4.20
- linux linux kernel4.20.1 and later · before 5.10.147
- linux linux kernel5.11 and later · before 5.15.71
- linux linux kernel5.16 and later · before 5.19.12
- linux linux kernel4.20
- linux linux kernel6.0
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 1ec2bf44c3770b9c3d510b1e78d50cd7fd19e8c5, b4c7c826709b7d882ec9b264d5032e887e6bd720, 4.20affected
- d6fd0ae25c6495674dc5a41a8d16bc8e0073276d and later · before 6ac5b52e3f352f9cb270c89e6e1d4dadb564ddb8affected · git
- d6fd0ae25c6495674dc5a41a8d16bc8e0073276d and later · before d8a76a2e514fbbb315a6dfff2d342de2de833994affected · git
- d6fd0ae25c6495674dc5a41a8d16bc8e0073276d and later · before c338bea1fec5504290dc0acf026c9e7dba25004baffected · git
- d6fd0ae25c6495674dc5a41a8d16bc8e0073276d and later · before a362bb864b8db4861977d00bd2c3222503ccc34baffected · git
- 4.14.120 and later · before 4.15affected · semver
- 4.19.12 and later · before 4.20affected · semver
- before 4.20not affected · semver
- 5.10.147 and later · up to and including 5.10.*not affected · semver
- 5.15.71 and later · up to and including 5.15.*not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | before 6.0.2-1 | 6.0.2-1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS | kernel-default-base | before 5.3.18-150200.24.209.1.150200.9.109.1 | 5.3.18-150200.24.209.1.150200.9.109.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS | kernel-docs | before 5.3.18-150200.24.209.2 | 5.3.18-150200.24.209.2 |
| SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS | kernel-obs-build | before 5.3.18-150200.24.209.1 | 5.3.18-150200.24.209.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS | kernel-preempt | before 5.3.18-150200.24.209.1 | 5.3.18-150200.24.209.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS | kernel-source | before 5.3.18-150200.24.209.1 | 5.3.18-150200.24.209.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS | kernel-syms | before 5.3.18-150200.24.209.1 | 5.3.18-150200.24.209.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS | kernel-64kb | before 5.3.18-150300.59.182.1 | 5.3.18-150300.59.182.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS | kernel-default-base | before 5.3.18-150300.59.182.1.150300.18.107.1 | 5.3.18-150300.59.182.1.150300.18.107.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS | kernel-docs | before 5.3.18-150300.59.182.2 | 5.3.18-150300.59.182.2 |
| SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS | kernel-obs-build | before 5.3.18-150300.59.182.1 | 5.3.18-150300.59.182.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS | kernel-preempt | before 5.3.18-150300.59.182.1 | 5.3.18-150300.59.182.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS | kernel-source | before 5.3.18-150300.59.182.1 | 5.3.18-150300.59.182.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS | kernel-syms | before 5.3.18-150300.59.182.1 | 5.3.18-150300.59.182.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-64kb | before 5.14.21-150400.24.141.1 | 5.14.21-150400.24.141.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-docs | before 5.14.21-150400.24.141.1 | 5.14.21-150400.24.141.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-obs-build | before 5.14.21-150400.24.141.1 | 5.14.21-150400.24.141.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-source | before 5.14.21-150400.24.141.1 | 5.14.21-150400.24.141.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-syms | before 5.14.21-150400.24.141.1 | 5.14.21-150400.24.141.1 |
| SUSE:Linux Enterprise Live Patching 12 SP5 | kernel-default | before 4.12.14-122.250.1 | 4.12.14-122.250.1 |
| SUSE:Linux Enterprise Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_66 | before 1-8.3.1 | 1-8.3.1 |
| SUSE:Linux Enterprise Live Patching 15 SP2 | kernel-default | before 5.3.18-150200.24.209.1 | 5.3.18-150200.24.209.1 |
| SUSE:Linux Enterprise Live Patching 15 SP2 | kernel-livepatch-SLE15-SP2_Update_54 | before 1-150200.5.3.1 | 1-150200.5.3.1 |
| SUSE:Linux Enterprise Live Patching 15 SP3 | kernel-default | before 5.3.18-150300.59.182.1 | 5.3.18-150300.59.182.1 |
+37
Same product
linux: all recordsOther highest-scoring records for the same primary product.
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- CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV83Now
- CVE-2019-13272In the Linux kernel before 5.1.17, ptrace_link in kernel/ptrace.c mishandles the recording of the credentials of a process that wants to creKEV77This week
- CVE-2013-6282The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the v6k and v7 ARM platforms do not validate certain addKEV77This week
- CVE-2013-2094The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9 uses an incorrect integer data type, which allows loKEV77This week
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 4.15 | Vendor (CNA) |
| Linux Linux | 4.20 | Vendor (CNA) |
| Linux Linux | 6ac5b52e3f352f9cb270c89e6e1d4dadb564ddb8 | Vendor (CNA) |
| Linux Linux | a362bb864b8db4861977d00bd2c3222503ccc34b | Vendor (CNA) |
| Linux Linux | c338bea1fec5504290dc0acf026c9e7dba25004b | Vendor (CNA) |
| Linux Linux | d8a76a2e514fbbb315a6dfff2d342de2de833994 | Vendor (CNA) |
| debian:linux | 6.0.2-1 · Debian:12 | Package registry (OSV) |
| opensuse:kernel-azure | 5.14.21-150500.33.72.1 · openSUSE:Leap 15.5 | Package registry (OSV) |
| opensuse:kernel-rt | 5.14.21-150500.13.76.1 · openSUSE:Leap Micro 5.5 | Package registry (OSV) |
| opensuse:kernel-source-azure | 5.14.21-150500.33.72.1 · openSUSE:Leap 15.5 | Package registry (OSV) |
| opensuse:kernel-syms-azure | 5.14.21-150500.33.72.1 · openSUSE:Leap 15.5 | Package registry (OSV) |
| suse:kernel-azure | 5.14.21-150500.33.72.1 · SUSE:Linux Enterprise Module for Public Cloud 15 SP5 | Package registry (OSV) |
| suse:kernel-livepatch-SLE15-SP5-RT_Update_22 | 1-150500.11.3.1 · SUSE:Linux Enterprise Live Patching 15 SP5 | Package registry (OSV) |
| suse:kernel-rt | 5.14.21-150500.13.76.1 · SUSE:Linux Enterprise Micro 5.5 | Package registry (OSV) |
| suse:kernel-rt_debug | 5.14.21-150500.13.76.1 · SUSE:Real Time Module 15 SP5 | Package registry (OSV) |
| suse:kernel-source-azure | 5.14.21-150500.33.72.1 · SUSE:Linux Enterprise Module for Public Cloud 15 SP5 | Package registry (OSV) |
| suse:kernel-source-rt | 5.14.21-150500.13.76.1 · SUSE:Linux Enterprise Micro 5.5 | Package registry (OSV) |
| suse:kernel-syms-azure | 5.14.21-150500.33.72.1 · SUSE:Linux Enterprise Module for Public Cloud 15 SP5 | Package registry (OSV) |
| suse:kernel-syms-rt | 5.14.21-150500.13.76.1 · SUSE:Real Time Module 15 SP5 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-24-0360 · Apr 29, 2024(Linux Kernel Güncellemesi)
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
—
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- git.kernel.org/stable/c/6ac5b52e3f352f9cb270c89e6e1d4dadb564ddb8
- git.kernel.org/stable/c/a362bb864b8db4861977d00bd2c3222503ccc34b
- git.kernel.org/stable/c/c338bea1fec5504290dc0acf026c9e7dba25004b
- git.kernel.org/stable/c/d8a76a2e514fbbb315a6dfff2d342de2de833994
Vendor advisories and official records. Exploit/PoC links are deliberately left out.