CVE Catalog

CVE-2026-93173

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel's BPF/LSM subsystem, security_bpf_prog_free() called from softirq context (via __bpf_prog_put_rcu) triggered a "sleeping function called from invalid context" BUG when a sleepable LSM program was attached to the hook. The fix drops bpf_prog_free from sleepable_lsm_hooks.

Risk Assessment

The bug may cause a system hang (BUG) when freeing BPF programs with attached sleepable LSM programs. Requires privileges to load BPF programs.

Recommendation

Update the Linux kernel to a version with the fix. Restrict loading of BPF/LSM programs to trusted users.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: bpf,lsm: Drop bpf_prog_free from sleepable_lsm_hooks __bpf_prog_put_rcu() is the call_rcu() callback for non-sleepable programs. security_bpf_prog_free() called from there fires bpf_prog_free in softirq; if a sleepable LSM prog is attached to that hook, might_fault() BUGs: BUG: sleeping function called from invalid context in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 5038 preempt_count: 101, expected: 0 Call Trace: <IRQ> __bpf_prog_enter_sleepable+0x1cd/0x320 kernel/bpf/trampoline.c:1255 bpf_trampoline_6442549705+0x53/0xd7 security_bpf_prog_free+0xde/0x130 security/security.c:5465 __bpf_prog_put_rcu+0xab/0xd0 kernel/bpf/syscall.c:2365 rcu_do_batch kernel/rcu/tree.c:2617 [inline] handle_softirqs+0x236/0x800 kernel/softirq.c:622 </IRQ> The call_rcu/call_rcu_tasks_trace split reflects the freed program's sleepability, not that of any attached observer. security_bpf_prog_free() also frees prog->aux->security, which has to stay after the grace period, so drop bpf_prog_free from sleepable_lsm_hooks rather than move the call. Non-sleepable observers still run there.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS