{"id":"CVE-2026-23134","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-23134","generatedAt":"2026-10-28T00:15:16.903Z","title":"In the Linux kernel, the following vulnerability has been resolved: slab: fix kmalloc_nolock() context check for PREEMPT_RT On PREEMPT_RT kernels, local_lock becomes a sleeping lock.","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nslab: fix kmalloc_nolock() context check for PREEMPT_RT\n\nOn PREEMPT_RT kernels, local_lock becomes a sleeping lock. The current\ncheck in kmalloc_nolock() only verifies we're not in NMI or hard IRQ\ncontext, but misses the case where preemption is disabled.\n\nWhen a BPF program runs from a tracepoint with preemption disabled\n(preempt_count > 0), kmalloc_nolock() proceeds to call\nlocal_lock_irqsave() which attempts to acquire a sleeping lock,\ntriggering:\n\n  BUG: sleeping function called from invalid context\n  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 6128\n  preempt_count: 2, expected: 0\n\nFix this by checking !preemptible() on PREEMPT_RT, which directly\nexpresses the constraint that we cannot take a sleeping lock when\npreemption is disabled. This encompasses the previous checks for NMI\nand hard IRQ contexts while also catching cases where preemption is\ndisabled.","published":"2026-02-14T16:15:53.000Z","lastModified":"2026-06-17T10:20:58.000Z","status":"Analyzed","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":5.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":[],"affected":["linux/linux kernel"],"epss":{"score":0.00126,"percentile":0.02247,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.13%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/99a3e3a1cfc93b8fe318c0a3a5cfb01f1d4ad53c","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f60ba4a97ae3f94e4818722ed2e4d260bbb17b44","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-23134","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}