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 E3B80C6FD18 for ; Tue, 28 Mar 2023 13:11:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232604AbjC1NLK (ORCPT ); Tue, 28 Mar 2023 09:11:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49240 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232475AbjC1NLJ (ORCPT ); Tue, 28 Mar 2023 09:11:09 -0400 X-Greylist: delayed 470 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Tue, 28 Mar 2023 06:10:32 PDT Received: from out-63.mta1.migadu.com (out-63.mta1.migadu.com [95.215.58.63]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B94493F9 for ; Tue, 28 Mar 2023 06:10:32 -0700 (PDT) Message-ID: <90d1ad90-028c-7fa2-70dd-09737eece60c@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1680008559; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jrgWfgmDvRPsXnaxvcypfwDf65oRjIFSf746iLMzzVA=; b=OwuWymanFlZrHSXooNsV67XYE+S/XMgnflxPYg4CnESYCHe6O9jkC8d7TUDtkNl3hydG2o wokZ/QsAneMKhNT42g9EWIhvsSoPqCC9olCCQ8bmhPVPf06F4cJOPesKAgEardcGBGgAq2 PqZyEZ9gqJtBNtsqyV7n2qGHU11PzCw= Date: Tue, 28 Mar 2023 21:02:27 +0800 MIME-Version: 1.0 Subject: Re: FAILED: patch "[PATCH] mm: kfence: fix using kfence_metadata without initialization" failed to apply to 5.15-stable tree To: gregkh@linuxfoundation.org, akpm@linux-foundation.org, dvyukov@google.com, elver@google.com, glider@google.com, jannh@google.com, sjpark@amazon.de, songmuchun@bytedance.com, stable@vger.kernel.org References: <16800049118459@kroah.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Muchun Song In-Reply-To: <16800049118459@kroah.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On 2023/3/28 20:01, gregkh@linuxfoundation.org wrote: > The patch below does not apply to the 5.15-stable tree. > If someone wants it applied there, or to any other stable or longterm > tree, then please email the backport, including the original git commit > id to . > > To reproduce the conflict and resubmit, you may use the following commands: > > git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y > git checkout FETCH_HEAD > git cherry-pick -x 1c86a188e03156223a34d09ce290b49bd4dd0403 > # > git commit -s > git send-email --to '' --in-reply-to '16800049118459@kroah.com' --subject-prefix 'PATCH 5.15.y' HEAD^.. > > Possible dependencies: > > 1c86a188e031 ("mm: kfence: fix using kfence_metadata without initialization in show_object()") > b33f778bba5e ("kfence: alloc kfence_pool after system startup") > 698361bca2d5 ("kfence: allow re-enabling KFENCE after system startup") > 07e8481d3c38 ("kfence: always use static branches to guard kfence_alloc()") > 08f6b10630f2 ("kfence: limit currently covered allocations when pool nearly full") > a9ab52bbcb52 ("kfence: move saving stack trace of allocations into __kfence_alloc()") > 9a19aeb56650 ("kfence: count unexpectedly skipped allocations") > > thanks, > > greg k-h > > ------------------ original commit in Linus's tree ------------------ > > From 1c86a188e03156223a34d09ce290b49bd4dd0403 Mon Sep 17 00:00:00 2001 > From: Muchun Song > Date: Wed, 15 Mar 2023 11:44:41 +0800 > Subject: [PATCH] mm: kfence: fix using kfence_metadata without initialization > in show_object() > > The variable kfence_metadata is initialized in kfence_init_pool(), then, > it is not initialized if kfence is disabled after booting. In this case, > kfence_metadata will be used (e.g. ->lock and ->state fields) without > initialization when reading /sys/kernel/debug/kfence/objects. There will > be a warning if you enable CONFIG_DEBUG_SPINLOCK. Fix it by creating > debugfs files when necessary. > > Link: https://lkml.kernel.org/r/20230315034441.44321-1-songmuchun@bytedance.com > Fixes: 0ce20dd84089 ("mm: add Kernel Electric-Fence infrastructure") > Signed-off-by: Muchun Song > Tested-by: Marco Elver > Reviewed-by: Marco Elver > Cc: Alexander Potapenko > Cc: Dmitry Vyukov > Cc: Jann Horn > Cc: SeongJae Park > Cc: > Signed-off-by: Andrew Morton > > diff --git a/mm/kfence/core.c b/mm/kfence/core.c > index 5349c37a5dac..79c94ee55f97 100644 > --- a/mm/kfence/core.c > +++ b/mm/kfence/core.c > @@ -726,10 +726,14 @@ static const struct seq_operations objects_sops = { > }; > DEFINE_SEQ_ATTRIBUTE(objects); > > -static int __init kfence_debugfs_init(void) > +static int kfence_debugfs_init(void) > { > - struct dentry *kfence_dir = debugfs_create_dir("kfence", NULL); > + struct dentry *kfence_dir; > > + if (!READ_ONCE(kfence_enabled)) > + return 0; > + > + kfence_dir = debugfs_create_dir("kfence", NULL); > debugfs_create_file("stats", 0444, kfence_dir, NULL, &stats_fops); > debugfs_create_file("objects", 0400, kfence_dir, NULL, &objects_fops); > return 0; > @@ -883,6 +887,8 @@ static int kfence_init_late(void) > } > > kfence_init_enable(); > + kfence_debugfs_init(); > + > return 0; > } > I have implemented a following patch based on v5.15 branch. From ba26f344fa3e477456a3cc60488a7b8e5af0e88d Mon Sep 17 00:00:00 2001 From: Muchun Song Date: Wed, 15 Mar 2023 11:44:41 +0800 Subject: [PATCH] mm: kfence: fix using kfence_metadata without initialization  in show_object() The variable kfence_metadata is initialized in kfence_init_pool(), then, it is not initialized if kfence is disabled after booting.  In this case, kfence_metadata will be used (e.g.  ->lock and ->state fields) without initialization when reading /sys/kernel/debug/kfence/objects.  There will be a warning if you enable CONFIG_DEBUG_SPINLOCK.  Fix it by creating debugfs files when necessary. Link: https://lkml.kernel.org/r/20230315034441.44321-1-songmuchun@bytedance.com Fixes: 0ce20dd84089 ("mm: add Kernel Electric-Fence infrastructure") Signed-off-by: Muchun Song Tested-by: Marco Elver Reviewed-by: Marco Elver Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Jann Horn Cc: SeongJae Park Cc: Signed-off-by: Andrew Morton ---  mm/kfence/core.c | 8 ++++++--  1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/mm/kfence/core.c b/mm/kfence/core.c index 39a6c434e355..573f34e6af0b 100644 --- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -678,10 +678,14 @@ static const struct file_operations objects_fops = {      .release = seq_release,  }; -static int __init kfence_debugfs_init(void) +static int kfence_debugfs_init(void)  { -    struct dentry *kfence_dir = debugfs_create_dir("kfence", NULL); +    struct dentry *kfence_dir; +    if (!READ_ONCE(kfence_enabled)) +        return 0; + +    kfence_dir = debugfs_create_dir("kfence", NULL);      debugfs_create_file("stats", 0444, kfence_dir, NULL, &stats_fops);      debugfs_create_file("objects", 0400, kfence_dir, NULL, &objects_fops);      return 0; -- 2.11.0