From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp153-166.sina.com.cn (smtp153-166.sina.com.cn [61.135.153.166]) (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 5A7E2179BD for ; Tue, 5 Aug 2025 02:28:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=61.135.153.166 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754360932; cv=none; b=IReGloFd8wqUtLHd9t/Q/iPezlRcD9QNU+3wXUIOjpVKADky4/YvWf2RwMW7ceCqeMi/iKYxe8ycO73XDqZlQdT3OpvIlxyOTGbGPAVczXTIxPai3wRF6nyyIS3lVVNjc1nZsOYcLuW7nmhox7zQOERYBzfUeMbq67ME6P8w89Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754360932; c=relaxed/simple; bh=sT8772EE7hv0HYnPqlBuhg4oI96t7ktCGAsGhlXbRAw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GIvxabMUi6DQPTnVijgNNlHo31FSAXKKlFNcIHi028zIGlvh6bJSCMvZ4jMm61zeueuaeiHgOffbllAkuqyNbauSgpmOaRN4e6K0oXiQZzk7mCwtXLj7HkmgA9Ca+FZCpu04s2SQniQv82C+8BWOXK5yuJ7MECi6GOXhVKyVKf8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com; spf=pass smtp.mailfrom=sina.com; dkim=pass (1024-bit key) header.d=sina.com header.i=@sina.com header.b=htZkPieC; arc=none smtp.client-ip=61.135.153.166 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=sina.com header.i=@sina.com header.b="htZkPieC" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sina.com; s=201208; t=1754360923; bh=9q4FNEh98n8QGO3XD+Gs9WYlWB8rKX/mHEa4vJlnv58=; h=From:Subject:Date:Message-ID; b=htZkPieCZyrE6iB/SNwOuUCZXwzUIkxV3ourIkqzpxmE7GZ4oTmXpjKCV/taxZEqx JOVvWev1cZkMybjurotAxO8zBmYcL4rZJRWixvzQgkb+1JvX8kbLkxhaMLn5JuToOw 174ouomgg+ZABy0695ILEERPE5+Ccl3UzwL/pmT8= X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([114.249.58.236]) by sina.com (10.54.253.33) with ESMTP id 68916C3200005072; Tue, 5 Aug 2025 10:28:05 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com Authentication-Results: sina.com; spf=none smtp.mailfrom=hdanton@sina.com; dkim=none header.i=none; dmarc=none action=none header.from=hdanton@sina.com X-SMAIL-MID: 1119176685383 X-SMAIL-UIID: 3ADC1206759D4182BDB67B0028505019-20250805-102805-1 From: Hillf Danton To: syzbot Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [kernfs?] possible deadlock in kernfs_remove Date: Tue, 5 Aug 2025 10:27:52 +0800 Message-ID: <20250805022753.3917-1-hdanton@sina.com> In-Reply-To: <6890f71a.050a0220.7f033.0010.GAE@google.com> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit > Date: Mon, 04 Aug 2025 11:08:26 -0700 [thread overview] > Hello, > > syzbot found the following issue on: > > HEAD commit: 759dfc7d04ba netlink: avoid infinite retry looping in netl.. > git tree: net > console+strace: https://syzkaller.appspot.com/x/log.txt?x=11332f82580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=ac0888b9ad46cd69 > dashboard link: https://syzkaller.appspot.com/bug?extid=2d7d0fbb5fb979113ff3 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1136d9bc580000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1536d9bc580000 #syz test upstream master --- x/fs/kernfs/mount.c +++ y/fs/kernfs/mount.c @@ -303,9 +303,7 @@ static int kernfs_fill_super(struct supe sb->s_shrink->seeks = 0; /* get root inode, initialize and unlock it */ - down_read(&kf_root->kernfs_rwsem); inode = kernfs_get_inode(sb, info->root->kn); - up_read(&kf_root->kernfs_rwsem); if (!inode) { pr_debug("kernfs: could not get root inode\n"); return -ENOMEM; --