From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793210800; b=zPkz5ElQNVsHet3HDn8Llnijs2LAczV1fHP/MlZZcceKOYSEHjKGXc+AU1kwqOoGo7qu tHG30ywpFN4Mm7mdo/qeUsK50l0bvaiQmE7pAZg/tBNT0B4wryDT093kFH9olhE3vRZ1F Vko84iSyl2oAYe7n50lhqG0PShFwDXMtm62V9QQqbj4ibx2RTvXgDLhMGkE9qBmHCeWNm 9kx6ywFtRC3hFN9s3VJ1DZFNMfgig4Tk2UT5xwgaZW/p6EJERR4FK7KuqghDJfxdrReE3 Vpf3a4fOwU/7hgk9SgFtVURBUvs3WAkhwBqQak8m3DfqgoHCvQ+2tI6wQvmSfGsMnog== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793210800; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=nOQOE01eFMTXAww+WoSTI6OoM9cMI74llXJeORzUy3Y=; b=KGM8WufyqjFaIUe0FDbWuGYeov3GsTH+HfPhI+3ewvJyk6CgLULretEyOpW81jOAIxzj 6BuFAyiE24cWhnw3JaxjiIShwCNc6stwNNl9zIhYiZj6S/VrisejAUV3afS2jTJrb68N7 MwYXyLFSrPGTJZ39/IQSswch9FdcoQUajx5CCc+irZJ9S5uCOP8ar4wWLn4Rp5oEytwUu cn3kYHtgRN8JUS9tJiduVk0O6gFE0OiptBtbU9yhf48hXV41pKQoPAaYAb4AG922mUEH/ O4k34AWhANp8otyC/bwwMdMD/9rkPfpdACRoP6J8xNExPWUr5pYwAOnCX7CQkMNCYzg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=iMzNSkoR; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 33C6D606A31D; Wed, 28 Oct 2026 18:06:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=iMzNSkoR Received: by smtp.kernel.org (Postfix) with ESMTPSA id 841771F01825; Wed, 28 Oct 2026 18:06:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793210800; bh=nOQOE01eFMTXAww+WoSTI6OoM9cMI74llXJeORzUy3Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=iMzNSkoRtaBpSG2pRVLHRmObl2EWv79qBfj+aD/bnjbpfDyb5JMC6H7gzekmK3yoL wyjToLWw7FRKJjqkRiWpfgvcZyW3qwVnp4GEIIqdcfNKl1ZcRlPOVs7+RlgEKUgo0S //CfrNRoDN68ucKTdv99xmAu8ZsV3MVqhk630To4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot , Tetsuo Handa , "Peter Zijlstra (Intel)" , Sasha Levin Subject: [PATCH 5.15 153/571] perf/core: Fix WARN in perf_sigtrap() Date: Wed, 28 Oct 2026 17:55:00 +0100 Message-ID: <20261028170011.646133381@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170008.009143722@linuxfoundation.org> References: <20261028170008.009143722@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tetsuo Handa [ Upstream commit 3da6bb419750f3ad834786d6ba7c9d5d062c770b ] 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 Signed-off-by: Tetsuo Handa Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/b1c224bd-97f9-462c-a3e3-125d5e19c983@I-love.SAKURA.ne.jp Signed-off-by: Sasha Levin --- 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 dc59568a538f6..40d31c3e1eb7a 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6691,18 +6691,18 @@ 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, -- 2.53.0