Linux: Improper Locking
CVE-2026-31467 is a high-severity improper locking vulnerability in Linux, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions d6565ea662e17d45a577184b0011bd69de22dc2b, d9d8360cb66e3b599d89d2526e7da8b530ebf2ff, 5c8ecdcfbfb0b0c6a82a4ebadc1ddea61609b902 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.38% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to d6565ea662e17d45a577184b0011bd69de22dc2b or d9d8360cb66e3b599d89d2526e7da8b530ebf2ff or 5c8ecdcfbfb0b0c6a82a4ebadc1ddea61609b902 or 378949f46e897204384f3f5f91e42e93e3f87568, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.15.203 or 6.1.168 or 6.6.131 or 6.12.80, whichever matches your release line, or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 648f2de053a882c87c05f0060f47d3b11841fdbe up to, but not including, d6565ea662e17d45a577184b0011bd69de22dc2b; 648f2de053a882c87c05f0060f47d3b11841fdbe up to, but not including, d9d8360cb66e3b599d89d2526e7da8b530ebf2ff; 648f2de053a882c87c05f0060f47d3b11841fdbe up to, but not including, 5c8ecdcfbfb0b0c6a82a4ebadc1ddea61609b902; 648f2de053a882c87c05f0060f47d3b11841fdbe up to, but not including, 378949f46e897204384f3f5f91e42e93e3f87568; 648f2de053a882c87c05f0060f47d3b11841fdbe up to, but not including, da40464064599eefe78749f75cd2bba371044c04; 648f2de053a882c87c05f0060f47d3b11841fdbe up to, but not including, e83e20b82859f0588e9a52a6fa9fea704a2061cf; 648f2de053a882c87c05f0060f47d3b11841fdbe up to, but not including, c23df30915f83e7257c8625b690a1cece94142a0; 5.13 | d6565ea662e17d45a577184b0011bd69de22dc2b, d9d8360cb66e3b599d89d2526e7da8b530ebf2ff, 5c8ecdcfbfb0b0c6a82a4ebadc1ddea61609b902, 378949f46e897204384f3f5f91e42e93e3f87568, da40464064599eefe78749f75cd2bba371044c04, e83e20b82859f0588e9a52a6fa9fea704a2061cf |
| Linux | Linux Kernel | 5.13 up to, but not including, 5.15.203; 5.16 up to, but not including, 6.1.168; 6.2 up to, but not including, 6.6.131; 6.7 up to, but not including, 6.12.80; 6.13 up to, but not including, 6.18.21; 6.19 up to, but not including, 6.19.11; 7.0 | 5.15.203, 6.1.168, 6.6.131, 6.12.80, 6.18.21, 6.19.11 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA.
Official description
In the Linux kernel, the following vulnerability has been resolved: erofs: add GFP_NOIO in the bio completion if needed The bio completion path in the process context (e.g. dm-verity) will directly call into decompression rather than trigger another workqueue context for minimal scheduling latencies, which can then call vm_map_ram() with GFP_KERNEL. Due to insufficient memory, vm_map_ram() may generate memory swapping I/O, which can cause submit_bio_wait to deadlock in some scenarios. Trimmed down the call stack, as follows: f2fs_submit_read_io submit_bio //bio_list is initialized. mmc_blk_mq_recovery z_erofs_endio vm_map_ram __pte_alloc_kernel __alloc_pages_direct_reclaim shrink_folio_list __swap_writepage submit_bio_wait //bio_list is non-NULL, hang!!! Use memalloc_noio_{save,restore}() to wrap up this path.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Locking
The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
How developers prevent this class of flaw
- Use industry standard APIs to implement locking mechanism.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/378949f46e897204384f3f5f91e42e93e3f87568
- git.kernel.org/stable/c/5c8ecdcfbfb0b0c6a82a4ebadc1ddea61609b902
- git.kernel.org/stable/c/c23df30915f83e7257c8625b690a1cece94142a0
- git.kernel.org/stable/c/d6565ea662e17d45a577184b0011bd69de22dc2b
- git.kernel.org/stable/c/d9d8360cb66e3b599d89d2526e7da8b530ebf2ff
- git.kernel.org/stable/c/da40464064599eefe78749f75cd2bba371044c04
- git.kernel.org/stable/c/e83e20b82859f0588e9a52a6fa9fea704a2061cf
Recent Improper Locking vulnerabilities
- 7.1 High severity
- 7.5 High severity
- 7.5 High severity
- 7.8 High severity
Apple Multiple Products Improper Locking Exploited
- 7.2 High severity
- 7.8 High severity
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