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 3EB0C1DF980 for ; Thu, 26 Jun 2025 21:49:23 +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=1750974571; cv=none; b=EDm+3vbc00DavrT/ZfWx5eDwse9cPHp6ITHB/zMB9wFrAkedH5VH3Ttp3pQeBOy2xl92cY0YmqU+9w+HKPthN10hPRX1p8lgQoUvMJ7bSTokwB3sCNyXUkFVyZd4khM4DZilq3ZRUt1f8AT+1RIKxZez6woOaKtdIhNWDMnWR5s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750974571; c=relaxed/simple; bh=g6sZmerK8T7Hdv5ZClE3SI2+XK1VoeRXN8e6HZTEhFg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TsQKx1pix1JVAiNbNdfxCxdFg4hfZXiL5VXDl78afefLluKwVPGsTDegyWGyaB6/mp6Pwh/R+OTeXrhE1T28OI542+BSXBzQLl9Ek45cY3Tas86g1hEA9K1yCf3C1hShICGfWINTDKwam+F/KQNtEGneaBvHfavioeiZH1z7qPE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com; spf=pass smtp.mailfrom=sina.com; arc=none smtp.client-ip=61.135.153.166 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com 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 685DC05800001F9E; Thu, 27 Jun 2025 05:49:14 +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: 3884156685177 X-SMAIL-UIID: 3BB5E0EC7E1043FBB1EBEE19B81E3801-20250627-054914-1 From: Hillf Danton To: syzbot Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [hams?] possible deadlock in nr_rt_ioctl (2) Date: Fri, 27 Jun 2025 05:49:01 +0800 Message-ID: <20250626214902.1880-1-hdanton@sina.com> In-Reply-To: <685d4c2a.a00a0220.2e5631.028c.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: Thu, 26 Jun 2025 06:33:30 -0700 > Hello, > > syzbot found the following issue on: > > HEAD commit: 09a0fa92e5b4 Merge tag 'selinux-pr-20250107' of git://git... > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=122714b0580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=7bdfbaac3fbb90d6 > dashboard link: https://syzkaller.appspot.com/bug?extid=14afda08dc3484d5db82 > compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17b8db0f980000 #syz test --- x/net/netrom/nr_route.c +++ y/net/netrom/nr_route.c @@ -331,6 +331,7 @@ static int nr_del_node(ax25_address *cal return -EINVAL; } + spin_lock_bh(&nr_neigh_list_lock); spin_lock_bh(&nr_node_list_lock); nr_node_lock(nr_node); for (i = 0; i < nr_node->count; i++) { @@ -339,7 +340,7 @@ static int nr_del_node(ax25_address *cal nr_neigh_put(nr_neigh); if (nr_neigh->count == 0 && !nr_neigh->locked) - nr_remove_neigh(nr_neigh); + __nr_remove_neigh(nr_neigh); nr_neigh_put(nr_neigh); nr_node->count--; @@ -361,6 +362,7 @@ static int nr_del_node(ax25_address *cal } nr_node_unlock(nr_node); spin_unlock_bh(&nr_node_list_lock); + spin_unlock_bh(&nr_neigh_list_lock); return 0; } @@ -368,6 +370,7 @@ static int nr_del_node(ax25_address *cal nr_neigh_put(nr_neigh); nr_node_unlock(nr_node); spin_unlock_bh(&nr_node_list_lock); + spin_unlock_bh(&nr_neigh_list_lock); nr_node_put(nr_node); return -EINVAL; --