From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2E48FEB64DD for ; Sun, 2 Jul 2023 19:51:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230017AbjGBTvC (ORCPT ); Sun, 2 Jul 2023 15:51:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32854 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232726AbjGBTut (ORCPT ); Sun, 2 Jul 2023 15:50:49 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0FE447AB3; Sun, 2 Jul 2023 12:46:34 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 000D260C90; Sun, 2 Jul 2023 19:40:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE172C433CB; Sun, 2 Jul 2023 19:40:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1688326837; bh=8hzbXpeCK4HcEryMW/YHb7rJOCxLtUYy75UHyDvoKsk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KmmeCb/doN/nrBDfnJwwtTBVI8mbrjWpHvCRxZT0knXaikCUClYvr4X5Rnmu3zyKL dP5vAzHH5lUol3dWf1TiP7/svlOrK8ipdAH1lwZGI0G0bi9QO9umb1bu9IbQ5aW33k lKuEzyVmHL9cJTeL0TIT+k/IzzEybWlm2V2i+P8Gl89aaTNL9I7h5mmGgFfLCU55bG KniCqxB68eZwEBUA3/IjZE1MwrirqE5WTSPhFEAdAiwrCBIlNhpS2cmHFbWI+5kKMR xSClPksGj8NaFq/G9rZMQKIme3MLiPuKxgJOCiclsy8rPHCV+mepbbwnB2pSOfQmRo whXphp05YNwRg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Tetsuo Handa , syzbot , Thomas Gleixner , Sasha Levin Subject: [PATCH AUTOSEL 6.4 05/15] debugobjects: Recheck debug_objects_enabled before reporting Date: Sun, 2 Jul 2023 15:40:10 -0400 Message-Id: <20230702194020.1776895-5-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230702194020.1776895-1-sashal@kernel.org> References: <20230702194020.1776895-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.4.1 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tetsuo Handa [ Upstream commit 8b64d420fe2450f82848178506d3e3a0bd195539 ] syzbot is reporting false a positive ODEBUG message immediately after ODEBUG was disabled due to OOM. [ 1062.309646][T22911] ODEBUG: Out of memory. ODEBUG disabled [ 1062.886755][ T5171] ------------[ cut here ]------------ [ 1062.892770][ T5171] ODEBUG: assert_init not available (active state 0) object: ffffc900056afb20 object type: timer_list hint: process_timeout+0x0/0x40 CPU 0 [ T5171] CPU 1 [T22911] -------------- -------------- debug_object_assert_init() { if (!debug_objects_enabled) return; db = get_bucket(addr); lookup_object_or_alloc() { debug_objects_enabled = 0; return NULL; } debug_objects_oom() { pr_warn("Out of memory. ODEBUG disabled\n"); // all buckets get emptied here, and } lookup_object_or_alloc(addr, db, descr, false, true) { // this bucket is already empty. return ERR_PTR(-ENOENT); } // Emits false positive warning. debug_print_object(&o, "assert_init"); } Recheck debug_object_enabled in debug_print_object() to avoid that. Reported-by: syzbot Suggested-by: Thomas Gleixner Signed-off-by: Tetsuo Handa Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/492fe2ae-5141-d548-ebd5-62f5fe2e57f7@I-love.SAKURA.ne.jp Closes: https://syzkaller.appspot.com/bug?extid=7937ba6a50bdd00fffdf Signed-off-by: Sasha Levin --- lib/debugobjects.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/lib/debugobjects.c b/lib/debugobjects.c index 984985c39c9b0..a517256a270b7 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -498,6 +498,15 @@ static void debug_print_object(struct debug_obj *obj, char *msg) const struct debug_obj_descr *descr = obj->descr; static int limit; + /* + * Don't report if lookup_object_or_alloc() by the current thread + * failed because lookup_object_or_alloc()/debug_objects_oom() by a + * concurrent thread turned off debug_objects_enabled and cleared + * the hash buckets. + */ + if (!debug_objects_enabled) + return; + if (limit < 5 && descr != descr_test) { void *hint = descr->debug_hint ? descr->debug_hint(obj->object) : NULL; -- 2.39.2