NVD / CVE Program· CNA Linux

CVE-2024-47691: f2fs: fix to avoid use-after-free in f2fs_stop_gc_thread()

Noroxi assessment

Priority: Monitor (action score 31/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.23% (FIRST EPSS).
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.
Fixed version: Linux Linux 7c339dee7eb0f8e4cadc317c595f898ef04dae30, c7f114d864ac91515bb07ac271e9824a20f5ed95, d79343cd66343709e409d96b2abb139a0a55ce34; azl3 kernel 6.6.51.1-5 on Azure Linux 3.0 6.6.56.1-5; azl3 kernel 6.6.56.1-5 on Azure Linux 3.0 6.6.56.1-5.

Low priority for now. Upgrade to Linux Linux 7c339dee7eb0f8e4cadc317c595f898ef04dae30, c7f114d864ac91515bb07ac271e9824a20f5ed95, d79343cd66343709e409d96b2abb139a0a55ce34; azl3 kernel 6.6.51.1-5 on Azure Linux 3.0 6.6.56.1-5; azl3 kernel 6.6.56.1-5 on Azure Linux 3.0 6.6.56.1-5 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid use-after-free in f2fs_stop_gc_thread() syzbot reports a f2fs bug as below: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_report+0xe8/0x550 mm/kasan/report.c:491 kasan_report+0x143/0x180 mm/kasan/report.c:601 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline] __refcount_add include/linux/refcount.h:184 [inline] __refcount_inc include/linux/refcount.h:241 [inline] refcount_inc include/linux/refcount.h:258 [inline] get_task_struct include/linux/sched/task.h:118 [inline] kthread_stop+0xca/0x630 kernel/kthread.c:704 f2fs_stop_gc_thread+0x65/0xb0 fs/f2fs/gc.c:210 f2fs_do_shutdown+0x192/0x540 fs/f2fs/file.c:2283 f2fs_ioc_shutdown fs/f2fs/file.c:2325 [inline] __f2fs_ioctl+0x443a/0xbe60 fs/f2fs/file.c:4325 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The root cause is below race condition, it may cause use-after-free issue in sbi->gc_th pointer. - remount - f2fs_remount - f2fs_stop_gc_thread - kfree(gc_th) - f2fs_ioc_shutdown - f2fs_do_shutdown - f2fs_stop_gc_thread - kthread_stop(gc_th->f2fs_gc_task) : sbi->gc_thread = NULL; We will call f2fs_do_shutdown() in two paths: - for f2fs_ioc_shutdown() path, we should grab sb->s_umount semaphore for fixing. - for f2fs_shutdown() path, it's safe since caller has already grabbed sb->s_umount semaphore.

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

Published: Oct 21, 2024
Updated: Jun 17, 2026
EPSS: 0.2% · 14th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 31 / 40 · 7.8 / 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.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

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 kernel4.16 and later · before 6.6.54
linux linux kernel6.7 and later · before 6.10.13
linux linux kernel6.11 and later · before 6.11.2

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
- 4.16affected
- 7950e9ac638e84518fbdd5c930939ad46a1068c5 and later · before fc18e655b62ac6bc9f12f5de0d749b4a3fe1e812affected · git
- 7950e9ac638e84518fbdd5c930939ad46a1068c5 and later · before 7c339dee7eb0f8e4cadc317c595f898ef04dae30affected · git
- 7950e9ac638e84518fbdd5c930939ad46a1068c5 and later · before d79343cd66343709e409d96b2abb139a0a55ce34affected · git
- 7950e9ac638e84518fbdd5c930939ad46a1068c5 and later · before c7f114d864ac91515bb07ac271e9824a20f5ed95affected · git
- before 4.16not affected · semver
- 6.6.54 and later · up to and including 6.6.*not affected · semver
- 6.10.13 and later · up to and including 6.10.*not affected · semver
- 6.11.2 and later · up to and including 6.11.*not affected · semver
- 6.12 and laternot affected · original_commit_for_fix

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	from 0	—
Debian:13	linux	before 6.11.2-1	6.11.2-1
openSUSE:Tumbleweed	kernel-source	before 6.11.8-1.1	6.11.8-1.1

Same product

linux: all records

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Published before and after this one in the same product

← EarlierCVE-2024-47689Oct 21, 2024 · f2fs: fix to don't set SB_RDONLY in f2fs_handle_critical_error()
21Monitor
← EarlierCVE-2024-47690Oct 21, 2024 · f2fs: get rid of online repaire on corrupted directory
22Monitor
Later →CVE-2024-47693Oct 21, 2024 · IB/core: Fix ib_cache_setup_one error flow cleanup
26Monitor

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	7c339dee7eb0f8e4cadc317c595f898ef04dae30	Vendor (CNA)
Linux Linux	c7f114d864ac91515bb07ac271e9824a20f5ed95	Vendor (CNA)
Linux Linux	d79343cd66343709e409d96b2abb139a0a55ce34	Vendor (CNA)
Linux Linux	fc18e655b62ac6bc9f12f5de0d749b4a3fe1e812	Vendor (CNA)
azl3 kernel 6.6.51.1-5 on Azure Linux 3.0	6.6.56.1-5 · CBL-Mariner Releases	Microsoft (MSRC)
azl3 kernel 6.6.56.1-5 on Azure Linux 3.0	6.6.56.1-5 · CBL-Mariner Releases	Microsoft (MSRC)
debian:linux	6.11.2-1 · Debian:13	Package registry (OSV)
opensuse:kernel-source	6.11.8-1.1 · openSUSE:Tumbleweed	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.

No history yet (it accumulates with the daily EPSS job).

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 researchers

Finders, 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).

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: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

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✗ → ✓Sep 28, 2026, 10:11 PM UTC

For records you follow, these changes also arrive as notifications. →

References

git.kernel.org/stable/c/7c339dee7eb0f8e4cadc317c595f898ef04dae30

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records