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 AB087346A0C; Tue, 21 Jul 2026 20:41:09 +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=1784666470; cv=none; b=HVu17icQeemI6YvDlpRHsrLcteG5BscLVKLg5bDq2litpf0pdEm4jC01FdQlD8HaTnW5fFXvG9H2OXWsANyS3viyV8hIQGYrwu+rk/NJZVbgy2/o8WfY/yHElpbudOnuopMestol2n7+3ndE6VNYc0u0NXkx60WCXW/utpTXung= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784666470; c=relaxed/simple; bh=UHwevlQ5nh3qqen7TqIXDNBUtdoQtqseCsT0xY+5fRA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oyOwb8A/3XuS2sK5Tc2DGDYk4ovU2Dm+BLvSleHbaoI4Am4q6Rq9TacqrylDnbElXkekFKgmR28pI7lam2MOLGqRFffxGp0Pv2CskuxGaNPuBCzoMVvbVKcIf5yhf8nCmk+mpRRW7wuU1P8w79sT592icae3j90Ijdj73ld+++Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=l7fg7Hbh; 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="l7fg7Hbh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1CA611F000E9; Tue, 21 Jul 2026 20:41:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784666469; bh=0zef729zvDD0jDLC4bX/oQBC2bxQzLQbX0ANXkVmfyo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=l7fg7HbhwIWAavcq/uPmHcTylHmAEQSh9GPo2hFoT+qZE6H+tNRVonBRl0grIsaS4 WXRfeJfdzWLpVM46m3jXmDw4Vuc4GVFQtVgJZaYoH7LPptAlnpxh5W7d1f0lKIu1nV q/u7jpA6DpXDkXmB8JIhSsHd9QFnonj9h9Eitj/k= 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 6.6 0642/1266] perf sched: Clean up idle_threads entry on init failure Date: Tue, 21 Jul 2026 17:17:59 +0200 Message-ID: <20260721152456.225333877@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152441.786066624@linuxfoundation.org> References: <20260721152441.786066624@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: 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 6df0d1252f197f..0a1a58f33ae651 100644 --- a/tools/perf/builtin-sched.c +++ b/tools/perf/builtin-sched.c @@ -2372,8 +2372,11 @@ 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