From nobody Fri Dec 19 16:11:11 2025 Received: from www262.sakura.ne.jp (www262.sakura.ne.jp [202.181.97.72]) (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 B03262E0916; Thu, 6 Nov 2025 11:20:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.181.97.72 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762428044; cv=none; b=txEFShJmubvWGDQ2s5X+V9gTR14SPRoINmSl8kSItG9lU297ludXBbyecI7d/xkn8JjcEQZYqR4KbTD8whhj+diz9HW69yTEGLqWC9LGKEt13iIK/5lcGGNSZ6Tw3pCZB1ibh5VUerspwIPhQmJdYo4cIZC0tuU8IwNOXLA0Xuo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762428044; c=relaxed/simple; bh=WiqShaaYOzXuSzUIhdMstXRb84zZxZUFhLhi/kXZ6jg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=RO5bdgCbAsKD4EhRK2B4+Sn5/aj96/8OGkzY6JRJPoCDJEzuGtKASWQ3ZPz27almey1SOuTdRqabYf4o4G1z2VsERiwu+/0EQYRh+QH+LICS4c941Y72LbYUoAOv0Dwns3k0nf/Jgw/6Xeujwx8IupMWBkl6CtZGZISpnzp/jmc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=I-love.SAKURA.ne.jp; spf=pass smtp.mailfrom=I-love.SAKURA.ne.jp; arc=none smtp.client-ip=202.181.97.72 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=I-love.SAKURA.ne.jp Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=I-love.SAKURA.ne.jp Received: from www262.sakura.ne.jp (localhost [127.0.0.1]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 5A6BKPPq045333; Thu, 6 Nov 2025 20:20:25 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Received: from [192.168.1.10] (M106072142033.v4.enabler.ne.jp [106.72.142.33]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id 5A6BKOvk045326 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NO); Thu, 6 Nov 2025 20:20:24 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Message-ID: Date: Thu, 6 Nov 2025 20:20:23 +0900 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: [PATCH] padata: use different lock_class_key for padata_list lock To: Herbert Xu Cc: syzbot , daniel.m.jordan@oracle.com, linux-kernel@vger.kernel.org, steffen.klassert@secunet.com, linux-crypto@vger.kernel.org References: <6860c5d3.a00a0220.c1739.0009.GAE@google.com> <68c34150.050a0220.3c6139.0045.GAE@google.com> <5823185b-55c6-416b-a85c-1191a045caf8@I-love.SAKURA.ne.jp> <60778a1e-c29d-4d41-8272-9e635d9ff427@I-love.SAKURA.ne.jp> Content-Language: en-US From: Tetsuo Handa In-Reply-To: Content-Transfer-Encoding: quoted-printable X-Virus-Status: clean X-Anti-Virus-Server: fsav401.rs.sakura.ne.jp Content-Type: text/plain; charset="utf-8" syzbot is reporting possibility of deadlock due to calling spin_lock_init() in __padata_list_init() from both padata_init_reorder_list() and padata_init_squeues(). This is a false positive, for reorder->lock is never the same as squeue->serial.lock. Reported-by: syzbot+bd936ccd4339cea66e6b@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=3Dbd936ccd4339cea66e6b Suggested-by: Herbert Xu Signed-off-by: Tetsuo Handa --- kernel/padata.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/padata.c b/kernel/padata.c index f4def028c48c..465d25020e1e 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -529,12 +529,14 @@ static void padata_init_squeues(struct parallel_data = *pd) /* Initialize per-CPU reorder lists */ static void padata_init_reorder_list(struct parallel_data *pd) { + static struct lock_class_key padata_list_key; int cpu; struct padata_list *list; =20 for_each_cpu(cpu, pd->cpumask.pcpu) { list =3D per_cpu_ptr(pd->reorder_list, cpu); __padata_list_init(list); + lockdep_set_class(&list->lock, &padata_list_key); } } =20 --=20 2.47.3