BPF programs can execute in all kinds of contexts and when a program running in a non-preemptible context uses the bpf_send_signal() kfunc, it will cause issues because this kfunc can sleep.
So change `irqs_disabled()` to `!preemptible()` that covers all edge cases: preempt_count() == 0 and irqs_disabled() Reported-by: [email protected] Closes: https://lore.kernel.org/all/[email protected]/ Fixes: 1bc7896e9ef4 ("bpf: Fix deadlock with rq_lock in bpf_send_signal()") Signed-off-by: Puranjay Mohan <[email protected]> --- kernel/trace/bpf_trace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 1b8db5aee9d3..d162c87e09a8 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -853,7 +853,7 @@ static int bpf_send_signal_common(u32 sig, enum pid_type type, struct task_struc if (unlikely(is_global_init(task))) return -EPERM; - if (irqs_disabled()) { + if (!preemptible()) { /* Do an early check on signal validity. Otherwise, * the error is lost in deferred irq_work. */ -- 2.40.1
