CVE-2025-40348 (GCVE-0-2025-40348)

Vulnerability from cvelistv5 – Published: 2025-12-16 13:30 – Updated: 2026-05-11 21:47
VLAI
Title
slab: Avoid race on slab->obj_exts in alloc_slab_obj_exts
Summary
In the Linux kernel, the following vulnerability has been resolved: slab: Avoid race on slab->obj_exts in alloc_slab_obj_exts If two competing threads enter alloc_slab_obj_exts() and one of them fails to allocate the object extension vector, it might override the valid slab->obj_exts allocated by the other thread with OBJEXTS_ALLOC_FAIL. This will cause the thread that lost this race and expects a valid pointer to dereference a NULL pointer later on. Update slab->obj_exts atomically using cmpxchg() to avoid slab->obj_exts overrides by racing threads. Thanks for Vlastimil and Suren's help with debugging.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 715b6a5b41dae39baeaa40d3386b548bb278b9c2 , < c7af5300d78460fc5037ddc77113ba3dbfe77dc0 (git)
Affected: 07e38a54cabd9b4de7ceb7f075f29ffa463e458a , < 7c34feda6a9a203c9744281f1b6671b7dad2012d (git)
Affected: f7381b9116407ba2a429977c80ff8df953ea9354 , < 6ed8bfd24ce1cb31742b09a3eb557cd008533eec (git)
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Linux Linux Affected: 6.12.54 , < 6.12.56 (semver)
Affected: 6.17.4 , < 6.17.6 (semver)
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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