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=-0.7 required=3.0 tests=FROM_LOCAL_HEX, 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 A0059C43387 for ; Thu, 20 Dec 2018 23:04:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6D2DD218FD for ; Thu, 20 Dec 2018 23:04:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732100AbeLTXEF (ORCPT ); Thu, 20 Dec 2018 18:04:05 -0500 Received: from mail-io1-f70.google.com ([209.85.166.70]:33179 "EHLO mail-io1-f70.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731692AbeLTXEE (ORCPT ); Thu, 20 Dec 2018 18:04:04 -0500 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g82mr97630jad.17.1545347043243; Thu, 20 Dec 2018 15:04:03 -0800 (PST) Date: Thu, 20 Dec 2018 15:04:03 -0800 In-Reply-To: <000000000000f16b5e05714225b8@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000009142a1057d7c2528@google.com> Subject: Re: KASAN: use-after-free Write in __xfrm_policy_unlink From: syzbot To: davem@davemloft.net, herbert@gondor.apana.org.au, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, steffen.klassert@secunet.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org syzbot has found a reproducer for the following crash on: HEAD commit: a9cd3439e3c6 neighbor: Use nda_policy for validating attri.. git tree: net-next console output: https://syzkaller.appspot.com/x/log.txt?x=16ff4a0d400000 kernel config: https://syzkaller.appspot.com/x/.config?x=1f6442435a55ea09 dashboard link: https://syzkaller.appspot.com/bug?extid=9d971dd21eb26567036b compiler: gcc (GCC) 8.0.1 20180413 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=118c7e1b400000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+9d971dd21eb26567036b@syzkaller.appspotmail.com 8021q: adding VLAN 0 to HW filter on device team0 8021q: adding VLAN 0 to HW filter on device team0 8021q: adding VLAN 0 to HW filter on device team0 8021q: adding VLAN 0 to HW filter on device team0 ================================================================== BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:704 [inline] BUG: KASAN: use-after-free in hlist_del_rcu include/linux/rculist.h:455 [inline] BUG: KASAN: use-after-free in __xfrm_policy_unlink+0xa09/0xa20 net/xfrm/xfrm_policy.c:2215 Write of size 8 at addr ffff8881b7071b50 by task syz-executor3/7764 CPU: 0 PID: 7764 Comm: syz-executor3 Not tainted 4.20.0-rc6+ #355 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+0x244/0x39d lib/dump_stack.c:113 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 __asan_report_store8_noabort+0x17/0x20 mm/kasan/report.c:438 __hlist_del include/linux/list.h:704 [inline] hlist_del_rcu include/linux/rculist.h:455 [inline] __xfrm_policy_unlink+0xa09/0xa20 net/xfrm/xfrm_policy.c:2215 xfrm_policy_insert+0x20a/0x850 net/xfrm/xfrm_policy.c:1587 pfkey_spdadd+0x10f8/0x19d0 net/key/af_key.c:2339 pfkey_process+0x851/0x9a0 net/key/af_key.c:2844 pfkey_sendmsg+0x5df/0xfb0 net/key/af_key.c:3683 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2116 __sys_sendmsg+0x11d/0x280 net/socket.c:2154 __do_sys_sendmsg net/socket.c:2163 [inline] __se_sys_sendmsg net/socket.c:2161 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2161 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457669 Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fea87c1ac78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457669 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fea87c1b6d4 R13: 00000000004c443a R14: 00000000004d7410 R15: 00000000ffffffff Allocated by task 7736: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 kmem_cache_alloc_trace+0x152/0x750 mm/slab.c:3620 kmalloc include/linux/slab.h:546 [inline] kzalloc include/linux/slab.h:741 [inline] xfrm_policy_alloc+0xfa/0x4f0 net/xfrm/xfrm_policy.c:383 pfkey_spdadd+0x244/0x19d0 net/key/af_key.c:2272 pfkey_process+0x851/0x9a0 net/key/af_key.c:2844 pfkey_sendmsg+0x5df/0xfb0 net/key/af_key.c:3683 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2116 __sys_sendmsg+0x11d/0x280 net/socket.c:2154 __do_sys_sendmsg net/socket.c:2163 [inline] __se_sys_sendmsg net/socket.c:2161 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2161 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 7753: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xcf/0x230 mm/slab.c:3817 xfrm_policy_destroy_rcu+0x4a/0x60 net/xfrm/xfrm_policy.c:407 __rcu_reclaim kernel/rcu/rcu.h:240 [inline] rcu_do_batch kernel/rcu/tree.c:2437 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2716 [inline] rcu_process_callbacks+0x100a/0x1ac0 kernel/rcu/tree.c:2697 __do_softirq+0x308/0xb7e kernel/softirq.c:292 The buggy address belongs to the object at ffff8881b7071b40 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 16 bytes inside of 1024-byte region [ffff8881b7071b40, ffff8881b7071f40) The buggy address belongs to the page: page:ffffea0006dc1c00 count:1 mapcount:0 mapping:ffff8881da800ac0 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000010200(slab|head) raw: 02fffc0000010200 ffffea0006da2088 ffffea0007624d08 ffff8881da800ac0 raw: 0000000000000000 ffff8881b7070040 0000000100000007 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881b7071a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881b7071a80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > ffff8881b7071b00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8881b7071b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881b7071c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================