{"id":"CVE-2025-40348","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nslab: Avoid race on slab->obj_exts in alloc_slab_obj_exts\n\nIf two competing threads enter alloc_slab_obj_exts() and one of them\nfails to allocate the object extension v…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nslab: Avoid race on slab->obj_exts in alloc_slab_obj_exts\n\nIf two competing threads enter alloc_slab_obj_exts() and one of them\nfails to allocate the object extension v…","severity":"none","published":"2025-12-16","updated":"2026-10-14","sourceUpdated":"2026-10-14T13:10:00.187","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-40348","references":[{"url":"https://git.kernel.org/stable/c/6ed8bfd24ce1cb31742b09a3eb557cd008533eec","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7c34feda6a9a203c9744281f1b6671b7dad2012d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c7af5300d78460fc5037ddc77113ba3dbfe77dc0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.00199,"epssPercentile":0.08999,"ingestedAt":"2026-10-14T13:30:58.437Z","slug":"CVE-2025-40348","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nslab: Avoid race on slab->obj_exts in alloc_slab_obj_exts\n\nIf two competing threads enter alloc_slab_obj_exts() and one of them\nfails to allocate the object extension vector, it might override the\nvalid slab->obj_exts allocated by the other thread with\nOBJEXTS_ALLOC_FAIL. This will cause the thread that lost this race and\nexpects a valid pointer to dereference a NULL pointer later on.\n\nUpdate slab->obj_exts atomically using cmpxchg() to avoid\nslab->obj_exts overrides by racing threads.\n\nThanks for Vlastimil and Suren's help with debugging.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}