gfs2: Fix use-after-free in gfs2_glock_shrink_scan
Priority LOW 34CWE-416Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 3 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.
Summary
In the Linux kernel, the following vulnerability has been resolved: gfs2: Fix use-after-free in gfs2_glock_shrink_scan The GLF_LRU flag is checked under lru_lock in gfs2_glock_remove_from_lru() to remove the glock from the lru list in __gfs2_glock_put(). On the shrink scan path, the same flag is cleared under lru_lock but because of cond_resched_lock(&lru_lock) in gfs2_dispose_glock_lru(), progress on the put side can be made without deleting the glock from the lru list. Keep GLF_LRU across the race window opened by cond_resched_lock(&lru_lock) to ensure correct behavior on both sides - clear GLF_LRU after list_del under lru_lock.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00243 15th percentileScored 2026-11-07
Fix Partial Linux (Linux): 4.4.274, 4.9.274, 4.14.238 +7Red Hat: 3 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 4.4.181 to before 4.4.274; 4.9.180 to before 4.9.274; 4.14.123 to before 4.14.238; 4.19.47 to before 4.19.196; 5.0.20 to before 5.1; 5.1.6 to before 5.2 | 4.4.274, 4.9.274, 4.14.238, 4.19.196, 5.1, 5.2 | Patch available | CNA |
| Linux | Linux | 5.2 and later | 4.4.274, 4.9.274, 4.14.238, 4.19.196, 5.4.127, 5.10.45, 5.12.12, 5.13 | Patch available | CNA |
- Linux VendorLinux Affected 4.4.181 to before 4.4.274; 4.9.180 to before 4.9.274; 4.14.123 to before 4.14.238; 4.19.47 to before 4.19.196; 5.0.20 to before 5.1; 5.1.6 to before 5.2 Fixed in 4.4.274, 4.9.274, 4.14.238, 4.19.196, 5.1, 5.2 Patch available CNA
- Linux VendorLinux Affected 5.2 and later Fixed in 4.4.274, 4.9.274, 4.14.238, 4.19.196, 5.4.127, 5.10.45, 5.12.12, 5.13 Patch available CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 4.4.181 to before 4.4.274; 4.9.180 to before 4.9.274; 4.14.123 to before 4.14.238; 4.19.47 to before 4.19.196; 5.0.20 to before 5.1; 5.1.6 to before 5.4.127; 5.5 to before 5.10.45; 5.11 to before 5.12.12 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:* | 5.13 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:* | 5.13 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:* | 5.13 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:* | 5.13 rc4 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.4.181 to before 4.4.274; 4.9.180 to before 4.9.274; 4.14.123 to before 4.14.238; 4.19.47 to before 4.19.196; 5.0.20 to before 5.1; 5.1.6 to before 5.4.127; 5.5 to before 5.10.45; 5.11 to before 5.12.12 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:* Versions 5.13 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:* Versions 5.13 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:* Versions 5.13 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:* Versions 5.13 rc4 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 4.4.274, 4.9.274, 4.14.238, 4.19.196, 5.1, 5.2
- Fix · CNA Linux (Linux) Fixed in 4.4.274, 4.9.274, 4.14.238, 4.19.196, 5.4.127, 5.10.45, 5.12.12, 5.13
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix planned: Will not fix |
Not affected: 1 product
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-47254
- 2026-10-03 Alias added: GHSA-g3v4-6rhh-7539
References
Patch 8
- https://git.kernel.org/stable/c/38ce329534500bf4ae71f81df6a37a406cf187b4
- https://git.kernel.org/stable/c/92869945cc5b78ee8a1ef90336fe070893e3458a
- https://git.kernel.org/stable/c/0364742decb0f02bc183404868b82896f7992595
- https://git.kernel.org/stable/c/094bf5670e762afa243d2c41a5c4ab71c7447bf4
- https://git.kernel.org/stable/c/86fd5b27db743a0ce0cc245e3a34813b2aa6ec1d
- https://git.kernel.org/stable/c/a61156314b66456ab6a291ed5deba1ebd002ab3c
- https://git.kernel.org/stable/c/e87ef30fe73e7e10d2c85bdcc778dcec24dca553
- https://git.kernel.org/stable/c/1ab19c5de4c537ec0d9b21020395a5b5a6c059b2
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2021-47254 · CVE Program
- CVE-2021-47254 · NVD
- FIRST EPSS
- GHSA-g3v4-6rhh-7539 · GitHub Advisory Database · CC BY 4.0
- CVE-2021-47254 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences