bpf: Add a recursion check to prevent loops in bpf_timer

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Do not schedule timer/wq operation on a cpu that is in irq_work
callback that is processing async_cmds queue.
Otherwise the following loop is possible:
bpf_timer_start() -> bpf_async_schedule_op() -> irq_work_queue().
irqrestore -> bpf_async_irq_worker() -> tracepoint -> bpf_timer_start().

Fixes: 1bfbc267ec ("bpf: Enable bpf_timer and bpf_wq in any context")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260204055147.54960-4-alexei.starovoitov@gmail.com

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Alexei Starovoitov 2026-02-03 21:51:46 -08:00 • committed by Andrii Nakryiko

parent 67ee5ad27d

commit 64873307e8

1 changed files with 16 additions and 0 deletions

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kernel/bpf/helpers.c

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