mm/kmemleak: avoid deadlock by moving pr_warn() outside kmemleak_lock
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 4 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-667 and the CVSS impact.
Summary
In the Linux kernel, the following vulnerability has been resolved: mm/kmemleak: avoid deadlock by moving pr_warn() outside kmemleak_lock When netpoll is enabled, calling pr_warn_once() while holding kmemleak_lock in mem_pool_alloc() can cause a deadlock due to lock inversion with the netconsole subsystem. This occurs because pr_warn_once() may trigger netpoll, which eventually leads to __alloc_skb() and back into kmemleak code, attempting to reacquire kmemleak_lock. This is the path for the deadlock. mem_pool_alloc() -> raw_spin_lock_irqsave(&kmemleak_lock, flags); -> pr_warn_once() -> netconsole subsystem -> netpoll -> __alloc_skb -> __create_object -> raw_spin_lock_irqsave(&kmemleak_lock, flags); Fix this by setting a flag and issuing the pr_warn_once() after kmemleak_lock is released.
Why it matters now
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 | 5.4 and later | 5.4.297, 5.10.241, 5.15.190, 6.1.149, 6.6.103, 6.12.43, 6.15.11, 6.16.2, 6.17 | Patch available | CNA |
- Linux VendorLinux Affected 5.4 and later Fixed in 5.4.297, 5.10.241, 5.15.190, 6.1.149, 6.6.103, 6.12.43, 6.15.11, 6.16.2, 6.17 Patch available CNA
CPE configurations NVD · 3
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.4 to before 5.4.297; 5.5 to before 5.10.241; 5.11 to before 5.15.190; 5.16 to before 6.1.149; 6.2 to before 6.6.103; 6.7 to before 6.12.43; 6.13 to before 6.15.11; 6.16 to before 6.16.2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* | 6.17 rc1 | Vulnerable | Linux |
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | 11.0 | Vulnerable | Debian |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.4 to before 5.4.297; 5.5 to before 5.10.241; 5.11 to before 5.15.190; 5.16 to before 6.1.149; 6.2 to before 6.6.103; 6.7 to before 6.12.43; 6.13 to before 6.15.11; 6.16 to before 6.16.2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* Versions 6.17 rc1 Vulnerable ·Linux
- cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.4.297, 5.10.241, 5.15.190, 6.1.149, 6.6.103, 6.12.43, 6.15.11, 6.16.2, 6.17
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 1 product
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2025-39736
- 2026-10-03 Alias added: GHSA-7g87-hx7m-ppg8
- 2026-11-05 CISA SSVC decision points changed
References
Patch 9
- https://git.kernel.org/stable/c/c7b6ea0ede687e7460e593c5ea478f50aa41682a
- https://git.kernel.org/stable/c/4b0151e1d468eb2667c37b7af99b3c075072d334
- https://git.kernel.org/stable/c/f249d32bb54876b4b6c3ae071af8ddca77af390b
- https://git.kernel.org/stable/c/62879faa8efe8d8a9c7bf7606ee9c068012d7dac
- https://git.kernel.org/stable/c/1da95d3d4b7b1d380ebd87b71a61e7e6aed3265d
- https://git.kernel.org/stable/c/a0854de00ce2ee27edf39037e7836ad580eb3350
- https://git.kernel.org/stable/c/08f70be5e406ce47c822f2dd11c1170ca259605b
- https://git.kernel.org/stable/c/a181b228b37a6a5625dad2bb4265bb7abb673e9f
- https://git.kernel.org/stable/c/47b0f6d8f0d2be4d311a49e13d2fd5f152f492b2
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- 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-2025-39736 · CVE Program
- CVE-2025-39736 · NVD
- FIRST EPSS
- GHSA-7g87-hx7m-ppg8 · GitHub Advisory Database · CC BY 4.0
- CVE-2025-39736 · 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