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 D15C843D4E2; Tue, 21 Jul 2026 22:10:27 +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=1784671828; cv=none; b=V2Gl9d3YLYEiVssdYvuLBVBeqS1HvIURaD38T9+7DxjVimDuBdecO9ZjBUWFrfagL3wKkLFifAfJo4lwCxx2mY3LjIGqBM35sG4MAq5I4I6kh5oVQ0JaOz61GGr+HeSbWeWUwIcBEvYuJw4K70B6Tr/wOXRPdOLYSgLloe8z3Mk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784671828; c=relaxed/simple; bh=ggW1GF8FPk2Bpi++wa9BaHJg1Oik4SoXaTeqWY/np0I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EhC4StH9ItDii24fOtYjANNQ1fJIquMs5WsiBKDf4xpnRIG0943Uxu2LWHAi0UDV4T0O55/+WBizALWnPR8SjLqAHW82Xtw8Cx5ls9Zl5iIe8VHmm5b0kZylylHYceiOLj7cvvK3lsYrlIBgMLNmvAHsX3tFrYRp8ArPT0J/fk8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=lWDD0AWg; 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="lWDD0AWg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3E0D71F000E9; Tue, 21 Jul 2026 22:10:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784671827; bh=sXK6wEN2oIDKDg2Q18n1+x3QJSDE4OiAuOnOKASkjBE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=lWDD0AWglssVISfwr2rmRfAmR5+yPiq+oraZadAe6pBkp4KiEAA829YZ/ToGJg+HB QeiHrEfZO3/b+oxLNwpIgZJRvlU6lRYvG/uTbv8wT2G2DztG2hdclc/Xwu54rU7fSZ RL54Ne4r8vCSqOIyhEwHeTl6n6ZnjjD9J2rEC9Lw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, sashiko-bot , David Ahern , Namhyung Kim , Arnaldo Carvalho de Melo , Sasha Levin Subject: [PATCH 5.15 393/843] perf sched: Clean up idle_threads entry on init failure Date: Tue, 21 Jul 2026 17:20:28 +0200 Message-ID: <20260721152414.881365609@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152405.946368001@linuxfoundation.org> References: <20260721152405.946368001@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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arnaldo Carvalho de Melo [ Upstream commit cda5a94ad9181cd60cbf04be11d524201bf489a2 ] get_idle_thread() allocates a thread via thread__new() and stores it in idle_threads[cpu], then calls init_idle_thread() to set up the private data. If init_idle_thread() fails (e.g. OOM for the idle_thread_runtime struct), the function returns NULL but leaves the partially initialized thread in idle_threads[cpu]. On subsequent calls for the same CPU, get_idle_thread() finds a non-NULL idle_threads[cpu], skips allocation, and returns thread__get() on a thread that has no priv data. Callers then get a thread whose thread__priv() returns NULL, leading to unexpected behavior. Release the thread and reset the slot to NULL on init failure so the entry doesn't persist in a corrupted state. Fixes: 49394a2a24c7 ("perf sched timehist: Introduce timehist command") Reported-by: sashiko-bot Cc: David Ahern Cc: Namhyung Kim Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/builtin-sched.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c index 35cc5339ede517..6264a2cded514f 100644 --- a/tools/perf/builtin-sched.c +++ b/tools/perf/builtin-sched.c @@ -2289,8 +2289,11 @@ static struct thread *get_idle_thread(int cpu) idle_threads[cpu] = thread__new(0, 0); if (idle_threads[cpu]) { - if (init_idle_thread(idle_threads[cpu]) < 0) + if (init_idle_thread(idle_threads[cpu]) < 0) { + /* clean up so next call doesn't find a half-initialized thread */ + thread__zput(idle_threads[cpu]); return NULL; + } } } -- 2.53.0