CVE-2026-23134

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> slab: fix kmalloc_nolock() context check for PREEMPT_RT<br /> <br /> On PREEMPT_RT kernels, local_lock becomes a sleeping lock. The current<br /> check in kmalloc_nolock() only verifies we&amp;#39;re not in NMI or hard IRQ<br /> context, but misses the case where preemption is disabled.<br /> <br /> When a BPF program runs from a tracepoint with preemption disabled<br /> (preempt_count &gt; 0), kmalloc_nolock() proceeds to call<br /> local_lock_irqsave() which attempts to acquire a sleeping lock,<br /> triggering:<br /> <br /> BUG: sleeping function called from invalid context<br /> in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 6128<br /> preempt_count: 2, expected: 0<br /> <br /> Fix this by checking !preemptible() on PREEMPT_RT, which directly<br /> expresses the constraint that we cannot take a sleeping lock when<br /> preemption is disabled. This encompasses the previous checks for NMI<br /> and hard IRQ contexts while also catching cases where preemption is<br /> disabled.