From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B22EA47ECDF; Sat, 12 Sep 2026 13:32:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789219944; cv=none; b=JJ2YKpVK0DldNaNWsag4Bi2OjL/SZ56LeHyWaX6VgoGKEan8R4/4ynoznG0/wpt3nflyxLsQNhZGqt48Y+XD1VgfW5ZzfP1+PLFLwnFXcM6i0fXKRP7krp3ipIBLm//YhrZXjioXpm2gyAYI+JLkKnHNyeMkhAumkGuulegxFAc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789219944; c=relaxed/simple; bh=jhc5AbbOn8nL7VBKagYPH/j7omrm6EAPWUmMgyQa+cA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CvPeqOokTe5IrtLnDhpqquvMr5FkzMgQFIUDBqZm206xlWcqpFnyepyLcOZs8mqnNQCmkjwKqOlRAGNXFMJLY+izfdvWRhB8nAWGddMxylpB1UlFHWkrFts4ddw0TL321D/5TpzLb95BGZPVSfcuP7As13WQoLCrgdIOHyeooBo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Zhly4BH7; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Zhly4BH7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 147AF1F000FF; Sat, 12 Sep 2026 13:32:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789219943; bh=6jD8PEGtgcq+KZC1DxfrRvDldb+6Kp0VtR/uv1zyRrk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Zhly4BH7sTjgeQ10hF45YhovIS5CKcd6vw7FuEcexEAyr+oNN5GzIvQ2SKP+9ywGW IDwFPMakwmGPxtNfW8vM1Hpl0xdo4KH3poWyXS+07sdiG39Jb8+NkxzECtSOSsfaRK j6EJDLG+RuQoh6YLjzQIQwoKoXKf5njn68rrc4SA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Hui Su , Steven Rostedt Subject: [PATCH 6.6 0023/1424] tracing: Fix crash passing ERR_PTR to kthread_stop() Date: Sat, 12 Sep 2026 08:40:55 +0200 Message-ID: <20260912065607.823004217@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.279695368@linuxfoundation.org> References: <20260912065607.279695368@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hui Su commit 649bc7df3e5d7be6f7996a95084037dbf3cad1e5 upstream. event_test_stuff() calls kthread_run() and unconditionally passes the returned task_struct pointer to kthread_stop(). kthread_run() returns an error pointer such as ERR_PTR(-ENOMEM) when kthread creation fails, for example under memory pressure during the boot-time event self-test. kthread_stop() then dereferences the invalid pointer, crashing the kernel. Check the result of kthread_run() before passing it to kthread_stop(). Use WARN_ON() so that a failure to create the self-test thread does not go unnoticed, matching the ring-buffer self-test fix in commit 91542863abad ("ring-buffer: Fix crash passing ERR_PTR to kthread_stop()"). Cc: stable@vger.kernel.org Fixes: e6187007d6c3 ("tracing/events: add startup tests for events") Link: https://patch.msgid.link/20260817120642.668375-3-sh_def@163.com Signed-off-by: Hui Su Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace_events.c | 2 ++ 1 file changed, 2 insertions(+) --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -4350,6 +4350,8 @@ static __init void event_test_stuff(void struct task_struct *test_thread; test_thread = kthread_run(event_test_thread, NULL, "test-events"); + if (WARN_ON(IS_ERR(test_thread))) + return; msleep(1); kthread_stop(test_thread); }