{"id":"CVE-2026-43285","summary":"mm/slab: do not access current-\u003emems_allowed_seq if !allow_spin","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/slab: do not access current-\u003emems_allowed_seq if !allow_spin\n\nLockdep complains when get_from_any_partial() is called in an NMI\ncontext, because current-\u003emems_allowed_seq is seqcount_spinlock_t and\nnot NMI-safe:\n\n  ================================\n  WARNING: inconsistent lock state\n  6.19.0-rc5-kfree-rcu+ #315 Tainted: G                 N\n  --------------------------------\n  inconsistent {INITIAL USE} -\u003e {IN-NMI} usage.\n  kunit_try_catch/9989 [HC1[1]:SC0[0]:HE0:SE1] takes:\n  ffff889085799820 (&____s-\u003eseqcount#3){.-.-}-{0:0}, at: ___slab_alloc+0x58f/0xc00\n  {INITIAL USE} state was registered at:\n    lock_acquire+0x185/0x320\n    kernel_init_freeable+0x391/0x1150\n    kernel_init+0x1f/0x220\n    ret_from_fork+0x736/0x8f0\n    ret_from_fork_asm+0x1a/0x30\n  irq event stamp: 56\n  hardirqs last  enabled at (55): [\u003cffffffff850a68d7\u003e] _raw_spin_unlock_irq+0x27/0x70\n  hardirqs last disabled at (56): [\u003cffffffff850858ca\u003e] __schedule+0x2a8a/0x6630\n  softirqs last  enabled at (0): [\u003cffffffff81536711\u003e] copy_process+0x1dc1/0x6a10\n  softirqs last disabled at (0): [\u003c0000000000000000\u003e] 0x0\n\n  other info that might help us debug this:\n   Possible unsafe locking scenario:\n\n         CPU0\n         ----\n    lock(&____s-\u003eseqcount#3);\n    \u003cInterrupt\u003e\n      lock(&____s-\u003eseqcount#3);\n\n   *** DEADLOCK ***\n\nAccording to Documentation/locking/seqlock.rst, seqcount_t is not\nNMI-safe and seqcount_latch_t should be used when read path can interrupt\nthe write-side critical section. In this case, do not access\ncurrent-\u003emems_allowed_seq and avoid retry.","modified":"2026-07-08T08:13:27.365187523Z","published":"2026-05-08T13:11:11.191Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43285.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/144080a5823b2dbd635acb6decf7ab23182664f3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/353dd9934447b9193643ae1afd938607a74d4915"},{"type":"WEB","url":"https://git.kernel.org/stable/c/efd767ddcef0669bbd33c6a823ea0a88f06d4b29"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43285.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43285"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"af92793e52c3a99b828ed4bdd277fd3e11c18d08"},{"fixed":"353dd9934447b9193643ae1afd938607a74d4915"},{"fixed":"efd767ddcef0669bbd33c6a823ea0a88f06d4b29"},{"fixed":"144080a5823b2dbd635acb6decf7ab23182664f3"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-43285.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.18.0"},{"fixed":"6.18.16"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-43285.json"}}],"schema_version":"1.7.5"}