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h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Vqa2C6+FY9WKWPbMW8C6oSWIKQJTQ6+YzQF4FBwiRPs=; b=tQ+p8NheBYyywPK4qCQeDvrtL8eTPYUHaSo35tanslSwho6BxIsdT6JBmlfnPiSonX C9oZifyN5n+svFZZEDh/MMKPijVfm4DDu15IQobbn385KB1aVOGo6+2FpqvS5QtkBhaI EsGQVSoA4MvnhGN9KW39gKNiuNB5aFgcPA0v0wArLEmrI+9fjDh9kBQszUjnf3+vv2JO 3DpcPe0KpENHYQIAbTsNJcaPqtEd9Kyg/JoOc2vLCdZdupKOhRhUhwo1vNapKTHw1sGd X6kmK30nLbr6YnJ/OHvVSPA71x4EGLuEoxD+LPGp9yFfFuuzMAbnTU8okKa3/n0mEifi 9Heg== X-Gm-Message-State: AHQUAua9RWRvt2dIesFqUiVwzT0qX/JDSQ/e3+xYEkSkfF/389Q+ufFh zp0gtTP1A+GfWMxGJnvj4sbdqCKmMHULAaDiDKI= X-Google-Smtp-Source: AHgI3IaP0WZy1qSYXSifjfdyQxLmIy4o5/6e8SSwLoSNjx2+rx5HqCxQmJxJsPUfZ7XY1WkUqZQ5DiLPxe6+XRdWJh4= X-Received: by 2002:a24:280a:: with SMTP id h10mr1115461ith.103.1550032567619; Tue, 12 Feb 2019 20:36:07 -0800 (PST) MIME-Version: 1.0 References: <0000000000002015db0581b71858@google.com> In-Reply-To: <0000000000002015db0581b71858@google.com> From: Xin Long Date: Wed, 13 Feb 2019 12:35:56 +0800 Message-ID: Subject: Re: KASAN: use-after-free Read in sctp_outq_tail To: syzbot Cc: davem , LKML , linux-sctp@vger.kernel.org, Marcelo Ricardo Leitner , network dev , Neil Horman , syzkaller-bugs , Vlad Yasevich 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 Wed, Feb 13, 2019 at 4:00 AM syzbot wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: d4104460aec1 Add linux-next specific files for 20190211 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=14140124c00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=c8a112d3b0d6719b > dashboard link: https://syzkaller.appspot.com/bug?extid=7823fa3f3e2d69341ea8 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+7823fa3f3e2d69341ea8@syzkaller.appspotmail.com > > ================================================================== > BUG: KASAN: use-after-free in list_add_tail include/linux/list.h:93 [inline] > BUG: KASAN: use-after-free in sctp_outq_tail_data net/sctp/outqueue.c:105 > [inline] > BUG: KASAN: use-after-free in sctp_outq_tail+0x816/0x930 > net/sctp/outqueue.c:313 > Read of size 8 at addr ffff88807b19a7b8 by task syz-executor.0/30745 I think https://patchwork.ozlabs.org/patch/1040500/ will fix this. > > CPU: 1 PID: 30745 Comm: syz-executor.0 Not tainted 5.0.0-rc5-next-20190211 > #32 > 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+0x172/0x1f0 lib/dump_stack.c:113 > print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 > kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 > __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 > list_add_tail include/linux/list.h:93 [inline] > sctp_outq_tail_data net/sctp/outqueue.c:105 [inline] > sctp_outq_tail+0x816/0x930 net/sctp/outqueue.c:313 > sctp_cmd_send_msg net/sctp/sm_sideeffect.c:1109 [inline] > sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1784 [inline] > sctp_side_effects net/sctp/sm_sideeffect.c:1220 [inline] > sctp_do_sm+0x68e/0x5380 net/sctp/sm_sideeffect.c:1191 > sctp_primitive_SEND+0xa0/0xd0 net/sctp/primitive.c:178 > sctp_sendmsg_to_asoc+0xa63/0x17b0 net/sctp/socket.c:1955 > sctp_sendmsg+0x10a9/0x17e0 net/sctp/socket.c:2113 > inet_sendmsg+0x147/0x5d0 net/ipv4/af_inet.c:798 > sock_sendmsg_nosec net/socket.c:621 [inline] > sock_sendmsg+0xdd/0x130 net/socket.c:631 > ___sys_sendmsg+0x806/0x930 net/socket.c:2136 > __sys_sendmsg+0x105/0x1d0 net/socket.c:2174 > __do_sys_sendmsg net/socket.c:2183 [inline] > __se_sys_sendmsg net/socket.c:2181 [inline] > __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2181 > do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x457e39 > Code: ad b8 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 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007fa9b8630c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e > RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457e39 > RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000003 > RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa9b86316d4 > R13: 00000000004c4e2b R14: 00000000004d8ab8 R15: 00000000ffffffff > > Allocated by task 30745: > save_stack+0x45/0xd0 mm/kasan/common.c:75 > set_track mm/kasan/common.c:87 [inline] > __kasan_kmalloc mm/kasan/common.c:498 [inline] > __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:471 > kasan_kmalloc+0x9/0x10 mm/kasan/common.c:506 > kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3615 > kmalloc include/linux/slab.h:548 [inline] > kzalloc include/linux/slab.h:743 [inline] > sctp_stream_init_ext+0x51/0x110 net/sctp/stream.c:172 > sctp_sendmsg_to_asoc+0x1273/0x17b0 net/sctp/socket.c:1896 > sctp_sendmsg+0x10a9/0x17e0 net/sctp/socket.c:2113 > inet_sendmsg+0x147/0x5d0 net/ipv4/af_inet.c:798 > sock_sendmsg_nosec net/socket.c:621 [inline] > sock_sendmsg+0xdd/0x130 net/socket.c:631 > ___sys_sendmsg+0x806/0x930 net/socket.c:2136 > __sys_sendmsg+0x105/0x1d0 net/socket.c:2174 > __do_sys_sendmsg net/socket.c:2183 [inline] > __se_sys_sendmsg net/socket.c:2181 [inline] > __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2181 > do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > Freed by task 30745: > save_stack+0x45/0xd0 mm/kasan/common.c:75 > set_track mm/kasan/common.c:87 [inline] > __kasan_slab_free+0x102/0x150 mm/kasan/common.c:460 > kasan_slab_free+0xe/0x10 mm/kasan/common.c:468 > __cache_free mm/slab.c:3491 [inline] > kfree+0xcf/0x230 mm/slab.c:3816 > sctp_stream_outq_migrate+0x3e6/0x540 net/sctp/stream.c:88 > sctp_stream_init+0xbc/0x410 net/sctp/stream.c:139 > sctp_process_init+0x21c3/0x2b20 net/sctp/sm_make_chunk.c:2466 > sctp_cmd_process_init net/sctp/sm_sideeffect.c:682 [inline] > sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1410 [inline] > sctp_side_effects net/sctp/sm_sideeffect.c:1220 [inline] > sctp_do_sm+0x3145/0x5380 net/sctp/sm_sideeffect.c:1191 > sctp_assoc_bh_rcv+0x343/0x660 net/sctp/associola.c:1074 > sctp_inq_push+0x1ea/0x290 net/sctp/inqueue.c:95 > sctp_backlog_rcv+0x196/0xbe0 net/sctp/input.c:354 > sk_backlog_rcv include/net/sock.h:937 [inline] > __release_sock+0x12e/0x3a0 net/core/sock.c:2379 > release_sock+0x59/0x1c0 net/core/sock.c:2895 > sctp_wait_for_connect+0x316/0x540 net/sctp/socket.c:8998 > sctp_sendmsg_to_asoc+0x13e3/0x17b0 net/sctp/socket.c:1967 > sctp_sendmsg+0x10a9/0x17e0 net/sctp/socket.c:2113 > inet_sendmsg+0x147/0x5d0 net/ipv4/af_inet.c:798 > sock_sendmsg_nosec net/socket.c:621 [inline] > sock_sendmsg+0xdd/0x130 net/socket.c:631 > ___sys_sendmsg+0x806/0x930 net/socket.c:2136 > __sys_sendmsg+0x105/0x1d0 net/socket.c:2174 > __do_sys_sendmsg net/socket.c:2183 [inline] > __se_sys_sendmsg net/socket.c:2181 [inline] > __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2181 > do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > The buggy address belongs to the object at ffff88807b19a780 > which belongs to the cache kmalloc-96 of size 96 > The buggy address is located 56 bytes inside of > 96-byte region [ffff88807b19a780, ffff88807b19a7e0) > The buggy address belongs to the page: > page:ffffea0001ec6680 count:1 mapcount:0 mapping:ffff88812c3f04c0 > index:0xffff88807b19a800 > flags: 0x1fffc0000000200(slab) > raw: 01fffc0000000200 ffffea000262acc8 ffffea0001448348 ffff88812c3f04c0 > raw: ffff88807b19a800 ffff88807b19a000 000000010000001d 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff88807b19a680: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > ffff88807b19a700: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > > ffff88807b19a780: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > ^ > ffff88807b19a800: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > ffff88807b19a880: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > ================================================================== > > > --- > 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#bug-status-tracking for how to communicate with > syzbot.