GHSA-GC4V-H3F5-H83F
Vulnerability from github – Published: 2026-02-14 18:30 – Updated: 2026-03-17 21:31In 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. The current check in kmalloc_nolock() only verifies we're not in NMI or hard IRQ context, but misses the case where preemption is disabled.
When a BPF program runs from a tracepoint with preemption disabled (preempt_count > 0), kmalloc_nolock() proceeds to call local_lock_irqsave() which attempts to acquire a sleeping lock, triggering:
BUG: sleeping function called from invalid context in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 6128 preempt_count: 2, expected: 0
Fix this by checking !preemptible() on PREEMPT_RT, which directly expresses the constraint that we cannot take a sleeping lock when preemption is disabled. This encompasses the previous checks for NMI and hard IRQ contexts while also catching cases where preemption is disabled.
{
"affected": [],
"aliases": [
"CVE-2026-23134"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-02-14T16:15:53Z",
"severity": "MODERATE"
},
"details": "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\u0027re 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 \u003e 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.",
"id": "GHSA-gc4v-h3f5-h83f",
"modified": "2026-03-17T21:31:41Z",
"published": "2026-02-14T18:30:14Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23134"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/99a3e3a1cfc93b8fe318c0a3a5cfb01f1d4ad53c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f60ba4a97ae3f94e4818722ed2e4d260bbb17b44"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
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