From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> mainline inclusion from mainline-v6.16-rc6 commit 3da6bb419750f3ad834786d6ba7c9d5d062c770b category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ICOXM0 CVE: CVE-2025-38424 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- Since exit_task_work() runs after perf_event_exit_task_context() updated ctx->task to TASK_TOMBSTONE, perf_sigtrap() from perf_pending_task() might observe event->ctx->task == TASK_TOMBSTONE. Swap the early exit tests in order not to hit WARN_ON_ONCE(). Closes: https://syzkaller.appspot.com/bug?extid=2fe61cb2a86066be6985 Reported-by: syzbot <syzbot+2fe61cb2a86066be6985@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/b1c224bd-97f9-462c-a3e3-125d5e19c983@I-love.SAKURA... Signed-off-by: Luo Gengkun <luogengkun2@huawei.com> --- kernel/events/core.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index b99ffd733674..eb567b5c4dee 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6737,18 +6737,18 @@ void perf_event_wakeup(struct perf_event *event) static void perf_sigtrap(struct perf_event *event) { /* - * We'd expect this to only occur if the irq_work is delayed and either - * ctx->task or current has changed in the meantime. This can be the - * case on architectures that do not implement arch_irq_work_raise(). + * Both perf_pending_task() and perf_pending_irq() can race with the + * task exiting. */ - if (WARN_ON_ONCE(event->ctx->task != current)) + if (current->flags & PF_EXITING) return; /* - * Both perf_pending_task() and perf_pending_irq() can race with the - * task exiting. + * We'd expect this to only occur if the irq_work is delayed and either + * ctx->task or current has changed in the meantime. This can be the + * case on architectures that do not implement arch_irq_work_raise(). */ - if (current->flags & PF_EXITING) + if (WARN_ON_ONCE(event->ctx->task != current)) return; send_sig_perf((void __user *)event->pending_addr, -- 2.34.1