ACPI: custom_method: fix potential use-after-free issue
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: 2 without a fix
Attack profile from CVSS 3.1 · NVD. 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: ACPI: custom_method: fix potential use-after-free issue In cm_write(), buf is always freed when reaching the end of the function. If the requested count is less than table.length, the allocated buffer will be freed but subsequent calls to cm_write() will still try to access it. Remove the unconditional kfree(buf) at the end of the function and set the buf to NULL in the -EINVAL error path to match the rest of function.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0023 13th percentileScored 2026-11-07
Fix Partial Linux (Linux): 4.4.269, 4.9.269, 4.14.233 +8Red Hat: 2 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 | 4.4.195 to before 4.4.269; 4.9.195 to before 4.9.269; 4.14.147 to before 4.14.233; 4.19.77 to before 4.19.191; 5.2.19 to before 5.3; 5.3.4 to before 5.4 | 4.4.269, 4.9.269, 4.14.233, 4.19.191, 5.3, 5.4 | Patch available | CNA |
| Linux | Linux | 5.4 and later | 4.4.269, 4.9.269, 4.14.233, 4.19.191, 5.4.118, 5.10.36, 5.11.20, 5.12.3, 5.13 | Patch available | CNA |
- Linux VendorLinux Affected 4.4.195 to before 4.4.269; 4.9.195 to before 4.9.269; 4.14.147 to before 4.14.233; 4.19.77 to before 4.19.191; 5.2.19 to before 5.3; 5.3.4 to before 5.4 Fixed in 4.4.269, 4.9.269, 4.14.233, 4.19.191, 5.3, 5.4 Patch available CNA
- Linux VendorLinux Affected 5.4 and later Fixed in 4.4.269, 4.9.269, 4.14.233, 4.19.191, 5.4.118, 5.10.36, 5.11.20, 5.12.3, 5.13 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 4.4.195 to before 4.4.269; 4.9.195 to before 4.9.269; 4.14.147 to before 4.14.233; 4.19.77 to before 4.19.191; 5.4 to before 5.4.118; 5.5 to before 5.10.36; 5.11 to before 5.11.20; 5.12 to before 5.12.3 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.4.195 to before 4.4.269; 4.9.195 to before 4.9.269; 4.14.147 to before 4.14.233; 4.19.77 to before 4.19.191; 5.4 to before 5.4.118; 5.5 to before 5.10.36; 5.11 to before 5.11.20; 5.12 to before 5.12.3 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 4.4.269, 4.9.269, 4.14.233, 4.19.191, 5.3, 5.4
- Fix · CNA Linux (Linux) Fixed in 4.4.269, 4.9.269, 4.14.233, 4.19.191, 5.4.118, 5.10.36, 5.11.20, 5.12.3, 5.13
Vendor assessments
Red Hat
Red Hat rating: Low. 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 |
Not affected: 2 products
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-46966
- 2026-10-03 Alias added: GHSA-8f8j-69c8-v223
References
Patch 9
- https://git.kernel.org/stable/c/1d53ca5d131074c925ce38361fb0376d3bf7e394
- https://git.kernel.org/stable/c/8b04d57f30caf76649d0567551589af9a66ca9be
- https://git.kernel.org/stable/c/90575d1d9311b753cf1718f4ce9061ddda7dfd23
- https://git.kernel.org/stable/c/a5b26a2e362f572d87e9fd35435680e557052a17
- https://git.kernel.org/stable/c/72814a94c38a33239793f7622cec6ace1e540c4b
- https://git.kernel.org/stable/c/62dc2440ebb552aa0d7f635e1697e077d9d21203
- https://git.kernel.org/stable/c/f16737caf41fc06cfe6e49048becb09657074d4b
- https://git.kernel.org/stable/c/b7a5baaae212a686ceb812c32fceed79c03c0234
- https://git.kernel.org/stable/c/e483bb9a991bdae29a0caa4b3a6d002c968f94aa
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-2021-46966 · CVE Program
- CVE-2021-46966 · NVD
- FIRST EPSS
- GHSA-8f8j-69c8-v223 · GitHub Advisory Database · CC BY 4.0
- CVE-2021-46966 · 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