CVE-2026-43285

/* * Conceptual Proof of Concept for CVE-2026-43285 * Triggering slab allocation in NMI context to reproduce the lockdep warning. */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/perf_event.h> #include <linux/nmi.h> // Dummy NMI handler to simulate the condition static void trigger_nmi_alloc(struct perf_event *event, struct perf_sample_data *data, struct pt_regs *regs) { // This allocation may eventually call get_from_any_partial() // which accesses current->mems_allowed_seq unsafely in NMI context. void *ptr = kmalloc(1024, GFP_ATOMIC); if (ptr) { kfree(ptr); } } static int __init poc_init_module(void) { printk(KERN_INFO "Loading PoC for CVE-2026-43285\n"); // In a real scenario, setup a perf event to call trigger_nmi_alloc frequently return 0; } static void __exit poc_cleanup_module(void) { printk(KERN_INFO "Unloading PoC for CVE-2026-43285\n"); } module_init(poc_init_module); module_exit(poc_cleanup_module); MODULE_LICENSE("GPL");

{"cve": {"id": "CVE-2026-43285", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-08T14:16:35.337", "lastModified": "2026-05-14T19:05:07.260", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/slab: do not access current->mems_allowed_seq if !allow_spin\n\nLockdep complains when get_from_any_partial() is called in an NMI\ncontext, because current->mems_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} -> {IN-NMI} usage.\n kunit_try_catch/9989 [HC1[1]:SC0[0]:HE0:SE1] takes:\n ffff889085799820 (&____s->seqcount#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): [<ffffffff850a68d7>] _raw_spin_unlock_irq+0x27/0x70\n hardirqs last disabled at (56): [<ffffffff850858ca>] __schedule+0x2a8a/0x6630\n softirqs last enabled at (0): [<ffffffff81536711>] copy_process+0x1dc1/0x6a10\n softirqs last disabled at (0): [<0000000000000000>] 0x0\n\n other info that might help us debug this:\n Possible unsafe locking scenario:\n\n CPU0\n ----\n lock(&____s->seqcount#3);\n <Interrupt>\n lock(&____s->seqcount#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->mems_allowed_seq and avoid retry."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18", "versionEndExcluding": "6.18.16", "matchCriteriaId": "E0D300DB-AA68-4962-981D-EF9F5E97AACF"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.6", "matchCriteriaId": "373EEEDA-FAA1-4FB4-B6ED-DB4DD99DBE67"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*", "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*", "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*", "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/144080a5823b2dbd635acb6decf7ab23182664f3", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/353dd9934447b9193643ae1afd938607a74d4915", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/efd767ddcef0669bbd33c6a823ea0a88f06d4b29", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}