Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751368AbeAPEoP (ORCPT + 1 other); Mon, 15 Jan 2018 23:44:15 -0500 Received: from mail-pf0-f195.google.com ([209.85.192.195]:44126 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750816AbeAPEoO (ORCPT ); Mon, 15 Jan 2018 23:44:14 -0500 X-Google-Smtp-Source: ACJfBosF4dfGNYMmHyAfC72KdQnjcLIn7sG6/ukg3ImaMHnSs7YJeT/pNQgS2rhSNcfAP8v3qNlTDu4LTHAeiYACKpc= MIME-Version: 1.0 In-Reply-To: <001a114454c0af5a300562dcbc51@google.com> References: <001a114454c0af5a300562dcbc51@google.com> From: Cong Wang Date: Mon, 15 Jan 2018 20:43:52 -0800 Message-ID: Subject: Re: KASAN: use-after-free Read in tipc_group_is_open To: syzbot Cc: David Miller , Jon Maloy , LKML , Linux Kernel Network Developers , syzkaller-bugs@googlegroups.com, tipc-discussion@lists.sourceforge.net, Ying Xue Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On Mon, Jan 15, 2018 at 7:58 PM, syzbot wrote: > Hello, > > syzkaller hit the following crash on > 594831a8aba3fd045c3212a3e3bb9788c77b989d > git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached > Raw console output is attached. > C reproducer is attached > syzkaller reproducer is attached. See https://goo.gl/kgGztJ > for information about syzkaller reproducers > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+799dafde0286795858ac@syzkaller.appspotmail.com > It will help syzbot understand when the bug is fixed. See footer for > details. > If you forward the report, please keep this part and the footer. > > ================================================================== > BUG: KASAN: use-after-free in tipc_group_is_open+0x3a/0x40 > net/tipc/group.c:106 > Read of size 1 at addr ffff8801d89f7378 by task syzkaller275009/3704 > > CPU: 0 PID: 3704 Comm: syzkaller275009 Not tainted 4.15.0-rc7+ #190 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:17 [inline] > dump_stack+0x194/0x257 lib/dump_stack.c:53 > print_address_description+0x73/0x250 mm/kasan/report.c:252 > kasan_report_error mm/kasan/report.c:351 [inline] > kasan_report+0x25b/0x340 mm/kasan/report.c:409 > __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:427 > tipc_group_is_open+0x3a/0x40 net/tipc/group.c:106 > tipc_poll+0x364/0x4d0 net/tipc/socket.c:740 commit eb929a91b213d2a72c5a8b4af9a1acf63bfb8287 Author: Jon Maloy Date: Mon Jan 8 21:03:31 2018 +0100 tipc: improve poll() for group member socket Apparently Jon's commit doesn't fix this. I also don't understand why Jon believes sock_poll_wait() could sync with setsockopt path... > sock_poll+0x141/0x320 net/socket.c:1111 > do_pollfd fs/select.c:822 [inline] > do_poll fs/select.c:872 [inline] > do_sys_poll+0x715/0x10b0 fs/select.c:966 > SYSC_poll fs/select.c:1024 [inline] > SyS_poll+0x10d/0x450 fs/select.c:1012 > entry_SYSCALL_64_fastpath+0x23/0x9a > RIP: 0033:0x446129 > RSP: 002b:00007f0f2df96db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000007 > RAX: ffffffffffffffda RBX: 00000000006dbc54 RCX: 0000000000446129 > RDX: 0000000000007fff RSI: 000000000000000a RDI: 0000000020ef5000 > RBP: 00000000006dbc50 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > R13: 00007ffc07e2923f R14: 00007f0f2df979c0 R15: 0000000000000007 > > Allocated by task 3702: > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 [inline] > kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 > kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3610 > kmalloc include/linux/slab.h:499 [inline] > kzalloc include/linux/slab.h:688 [inline] > tipc_group_create+0x144/0x900 net/tipc/group.c:180 > tipc_sk_join net/tipc/socket.c:2762 [inline] > tipc_setsockopt+0x274/0xce0 net/tipc/socket.c:2877 > SYSC_setsockopt net/socket.c:1823 [inline] > SyS_setsockopt+0x189/0x360 net/socket.c:1802 > entry_SYSCALL_64_fastpath+0x23/0x9a > > Freed by task 3702: > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 [inline] > kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 > __cache_free mm/slab.c:3488 [inline] > kfree+0xd6/0x260 mm/slab.c:3803 > tipc_group_delete+0x2c8/0x3d0 net/tipc/group.c:234 > tipc_sk_join net/tipc/socket.c:2775 [inline] > tipc_setsockopt+0xaa9/0xce0 net/tipc/socket.c:2877 > SYSC_setsockopt net/socket.c:1823 [inline] > SyS_setsockopt+0x189/0x360 net/socket.c:1802 > entry_SYSCALL_64_fastpath+0x23/0x9a > > The buggy address belongs to the object at ffff8801d89f7300 > which belongs to the cache kmalloc-128 of size 128 > The buggy address is located 120 bytes inside of > 128-byte region [ffff8801d89f7300, ffff8801d89f7380) > The buggy address belongs to the page: > page:ffffea0007627dc0 count:1 mapcount:0 mapping:ffff8801d89f7000 index:0x0 > flags: 0x2fffc0000000100(slab) > raw: 02fffc0000000100 ffff8801d89f7000 0000000000000000 0000000100000015 > raw: ffffea0007622720 ffffea0007627ce0 ffff8801dac00640 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8801d89f7200: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb > ffff8801d89f7280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >> >> ffff8801d89f7300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ^ > ffff8801d89f7380: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 > ffff8801d89f7400: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc > ================================================================== > > > --- > This bug is generated by a dumb bot. It may contain errors. > See https://goo.gl/tpsmEJ for details. > Direct all questions to syzkaller@googlegroups.com. > > syzbot will keep track of this bug report. > If you forgot to add the Reported-by tag, once the fix for this bug is > merged > into any tree, please reply to this email with: > #syz fix: exact-commit-title > If you want to test a patch for this bug, please reply with: > #syz test: git://repo/address.git branch > and provide the patch inline or as an attachment. > To mark this as a duplicate of another syzbot report, please reply with: > #syz dup: exact-subject-of-another-report > If it's a one-off invalid bug report, please reply with: > #syz invalid > Note: if the crash happens again, it will cause creation of a new bug > report. > Note: all commands must start from beginning of the line in the email body.