__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.
Fixes: 1b67772e4e ("bpf,lsm: Refactor bpf_prog_alloc/bpf_prog_free LSM hooks")
Signed-off-by: Sechang Lim <rhkrqnwk98@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260701080757.1394144-1-rhkrqnwk98@gmail.com
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