tjh.dev / kernel
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
1
fork

Configure Feed

Select the types of activity you want to include in your feed.

bpf: Send signals asynchronously if !preemptible

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.
Change `irqs_disabled()` to `!preemptible()`.

Reported-by: syzbot+97da3d7e0112d59971de@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/67486b09.050a0220.253251.0084.GAE@google.com/
Fixes: 1bc7896e9ef4 ("bpf: Fix deadlock with rq_lock in bpf_send_signal()")
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250115103647.38487-1-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

authored by

Puranjay Mohan and committed by
Alexei Starovoitov 87c54410 9fe17b74

+1 -1
+1 -1
kernel/trace/bpf_trace.c
··· 842 842 if (unlikely(is_global_init(task))) 843 843 return -EPERM; 844 844 845 - if (irqs_disabled()) { 845 + if (!preemptible()) { 846 846 /* Do an early check on signal validity. Otherwise, 847 847 * the error is lost in deferred irq_work. 848 848 */