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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C4E2C43381 for ; Sat, 30 Mar 2019 14:18:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C95CC2183F for ; Sat, 30 Mar 2019 14:18:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="K8bfn1rO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730911AbfC3OSq (ORCPT ); Sat, 30 Mar 2019 10:18:46 -0400 Received: from mail-wm1-f66.google.com ([209.85.128.66]:51909 "EHLO mail-wm1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730838AbfC3OSp (ORCPT ); Sat, 30 Mar 2019 10:18:45 -0400 Received: by mail-wm1-f66.google.com with SMTP id 4so5410664wmf.1; Sat, 30 Mar 2019 07:18:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=46wkvm0w5QxqlVYof1WHt4ADpelrKMDMx5zOPv8wNxk=; b=K8bfn1rO3MaJLqejsWAwv0YGYA7F3ebPmKxOMAHptXXij3D/TZar+YqBWHELV28Z+w IFmQyGZz7OEsX1UkBO37+olpmYe/y0f0wEuZAB97JjE++l9S4/NNrQONTrZBbfrpLlWy Yo4PZsNVEF1jw3QcwqgtB3M6lQH00fo51aCur40RC4aOH33elzxizUJI4h9QVDRY0IbK RtcjDPtctM8Nr5XGDpWw6zBjHywudoWbSCLcoAU6vHsN9muimk46FH8uRvcGmeVY1fSh sHDZh9NymZfypuqXmikYsL3vgAuJ5XjkTQIJ8WUMOltGJtmVxiZcaI00X5c6mnW2dhLU J6Tg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=46wkvm0w5QxqlVYof1WHt4ADpelrKMDMx5zOPv8wNxk=; b=TWj+yU0u0wONkhcBJoBssvXloDLGLpm7HLoR/OtE2t7kJOHWDQKSFDUZi9RdY5wCks vs0oPSkxZLpUrsirtXb+n1guasxyvneVu3k3S31lqx8oTbRkS8VBeU+15K+z6/KPz8sV HlZKJ641EVR30RGvQ51Td1amkdXRk8EVYcfJFsEBnjoNZxGrIy8Bf9mxsFhrxtR94o56 bYPWh1ZvuWAfeex31gxf2b6FLccfy3kC3kD7Ze+emdKcO6j9LfyQ71KKZw1ewGsEh73P LTQjx77VGBCK46plwJPKUyp3CPkLxWByN4P9VrdgE0kdHkiLE3j9k8wSC/F+XVq4Klc5 TTqw== X-Gm-Message-State: APjAAAVDgGRksFh3N/tKwY2qUtxRDWoHrDPl05We5RaOneWJGCimnTEu h0VVYqej3z4rwkINZpLrp8QFFHz8koZ2X9ebAfo= X-Google-Smtp-Source: APXvYqzN17hDQf0Q2OFsteCv0+4GfSx91BujUEMNw3r5Ugp5mqhxGHq7RPJoFGD77wyMU8adcpsy16amK9Pvs4e0iJ4= X-Received: by 2002:a1c:c401:: with SMTP id u1mr6622777wmf.129.1553955523267; Sat, 30 Mar 2019 07:18:43 -0700 (PDT) MIME-Version: 1.0 References: <000000000000cfda050585171f3b@google.com> In-Reply-To: <000000000000cfda050585171f3b@google.com> From: Xin Long Date: Sat, 30 Mar 2019 22:18:32 +0800 Message-ID: Subject: Re: KMSAN: uninit-value in tipc_nl_compat_bearer_enable (2) To: syzbot Cc: davem , Alexander Potapenko , Jon Maloy , LKML , network dev , syzkaller-bugs , tipc-discussion@lists.sourceforge.net, Ying Xue Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 28, 2019 at 1:55 AM syzbot wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: 9536b452 kmsan: uaccess.h: fix variable name conflicts > git tree: kmsan > console output: https://syzkaller.appspot.com/x/log.txt?x=15f5d583200000 > kernel config: https://syzkaller.appspot.com/x/.config?x=a5675814e8eae69e > dashboard link: https://syzkaller.appspot.com/bug?extid=8b707430713eb46e1e45 > compiler: clang version 8.0.0 (trunk 350509) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16438e1b200000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16898cd7200000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+8b707430713eb46e1e45@syzkaller.appspotmail.com > > ================================================================== > BUG: KMSAN: uninit-value in memchr+0xce/0x110 lib/string.c:961 > CPU: 0 PID: 10526 Comm: syz-executor961 Not tainted 5.0.0+ #13 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x173/0x1d0 lib/dump_stack.c:113 > kmsan_report+0x12e/0x2a0 mm/kmsan/kmsan.c:600 > __msan_warning+0x82/0xf0 mm/kmsan/kmsan_instr.c:313 > memchr+0xce/0x110 lib/string.c:961 > string_is_valid net/tipc/netlink_compat.c:176 [inline] > tipc_nl_compat_bearer_enable+0x2c4/0x910 net/tipc/netlink_compat.c:401 It's using the wrong length to check if b->name is valid when b->name size < TIPC_MAX_BEARER_NAME. The right count should start from tipc_bearer_config->name. diff --git a/net/tipc/netlink_compat.c b/net/tipc/netlink_compat.c index 4ad3586..895f368 100644 --- a/net/tipc/netlink_compat.c +++ b/net/tipc/netlink_compat.c @@ -397,7 +397,9 @@ static int tipc_nl_compat_bearer_enable(struct tipc_nl_compat_cmd_doit *cmd, if (!bearer) return -EMSGSIZE; - len = min_t(int, TLV_GET_DATA_LEN(msg->req), TIPC_MAX_BEARER_NAME); + len = TLV_GET_DATA_LEN(msg->req); + len -= offsetof(struct tipc_bearer_config, name); + len = min_t(int, len, TIPC_MAX_BEARER_NAME); if (!string_is_valid(b->name, len)) return -EINVAL; The simliar thing should be done in: tipc_nl_compat_media_set() tipc_nl_compat_bearer_set() tipc_nl_compat_link_set() > __tipc_nl_compat_doit net/tipc/netlink_compat.c:321 [inline] > tipc_nl_compat_doit+0x3aa/0xaf0 net/tipc/netlink_compat.c:354 > tipc_nl_compat_handle net/tipc/netlink_compat.c:1162 [inline] > tipc_nl_compat_recv+0x1ae7/0x2750 net/tipc/netlink_compat.c:1265 > genl_family_rcv_msg net/netlink/genetlink.c:601 [inline] > genl_rcv_msg+0x185f/0x1a60 net/netlink/genetlink.c:626 > netlink_rcv_skb+0x431/0x620 net/netlink/af_netlink.c:2477 > genl_rcv+0x63/0x80 net/netlink/genetlink.c:637 > netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] > netlink_unicast+0xf3e/0x1020 net/netlink/af_netlink.c:1336 > netlink_sendmsg+0x127f/0x1300 net/netlink/af_netlink.c:1917 > sock_sendmsg_nosec net/socket.c:622 [inline] > sock_sendmsg net/socket.c:632 [inline] > ___sys_sendmsg+0xdb9/0x11b0 net/socket.c:2115 > __sys_sendmsg net/socket.c:2153 [inline] > __do_sys_sendmsg net/socket.c:2162 [inline] > __se_sys_sendmsg+0x305/0x460 net/socket.c:2160 > __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2160 > do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291 > entry_SYSCALL_64_after_hwframe+0x63/0xe7 > RIP: 0033:0x440209 > Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 > 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff > ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007ffc77bfd0a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e > RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440209 > RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000003 > RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401a90 > R13: 0000000000401b20 R14: 0000000000000000 R15: 0000000000000000 > > Uninit was created at: > kmsan_save_stack_with_flags mm/kmsan/kmsan.c:205 [inline] > kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:159 > kmsan_kmalloc+0xa6/0x130 mm/kmsan/kmsan_hooks.c:176 > kmsan_slab_alloc+0xe/0x10 mm/kmsan/kmsan_hooks.c:185 > slab_post_alloc_hook mm/slab.h:445 [inline] > slab_alloc_node mm/slub.c:2773 [inline] > __kmalloc_node_track_caller+0xe9e/0xff0 mm/slub.c:4398 > __kmalloc_reserve net/core/skbuff.c:140 [inline] > __alloc_skb+0x309/0xa20 net/core/skbuff.c:208 > alloc_skb include/linux/skbuff.h:1012 [inline] > netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline] > netlink_sendmsg+0xb82/0x1300 net/netlink/af_netlink.c:1892 > sock_sendmsg_nosec net/socket.c:622 [inline] > sock_sendmsg net/socket.c:632 [inline] > ___sys_sendmsg+0xdb9/0x11b0 net/socket.c:2115 > __sys_sendmsg net/socket.c:2153 [inline] > __do_sys_sendmsg net/socket.c:2162 [inline] > __se_sys_sendmsg+0x305/0x460 net/socket.c:2160 > __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2160 > do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291 > entry_SYSCALL_64_after_hwframe+0x63/0xe7 > ================================================================== > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches