> -----Original Message----- > From: syzbot <syzbot+9845fed98688e01f4...@syzkaller.appspotmail.com> > Sent: 12-Dec-18 06:11 > To: da...@davemloft.net; Jon Maloy <jon.ma...@ericsson.com>; linux- > ker...@vger.kernel.org; netdev@vger.kernel.org; syzkaller- > b...@googlegroups.com; tipc-discuss...@lists.sourceforge.net; > ying....@windriver.com > Subject: KASAN: use-after-free Read in tipc_group_cong
This seems to be an effect of the same bug as reported in https://syzkaller.appspot.com/bug?extid=10a9db47c3a0e13eb31c Cong posted a fix for that one. Did you see the crash after applying his patch? ///jon > > Hello, > > syzbot found the following crash on: > > HEAD commit: f5d582777bcb Merge branch 'for-linus' of git://git.kernel... > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=1705d525400000 > kernel config: https://syzkaller.appspot.com/x/.config?x=c8970c89a0efbb23 > dashboard link: > https://syzkaller.appspot.com/bug?extid=9845fed98688e01f431e > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=101b6ba3400000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+9845fed98688e01f4...@syzkaller.appspotmail.com > > 8021q: adding VLAN 0 to HW filter on device team0 > 8021q: adding VLAN 0 to HW filter on device team0 > audit: type=1400 audit(1544592509.246:38): avc: denied { associate } for > pid=6204 comm="syz-executor5" name="syz5" > scontext=unconfined_u:object_r:unlabeled_t:s0 > tcontext=system_u:object_r:unlabeled_t:s0 tclass=filesystem permissive=1 > ========================================================== > ======== > BUG: KASAN: use-after-free in tipc_group_find_dest net/tipc/group.c:255 > [inline] > BUG: KASAN: use-after-free in tipc_group_cong+0x566/0x5d0 > net/tipc/group.c:416 > Read of size 8 at addr ffff8881c59f5000 by task syz-executor4/10565 > > CPU: 1 PID: 10565 Comm: syz-executor4 Not tainted 4.20.0-rc6+ #151 > 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_load8_noabort+0x14/0x20 mm/kasan/report.c:433 > tipc_group_find_dest net/tipc/group.c:255 [inline] > tipc_group_cong+0x566/0x5d0 net/tipc/group.c:416 > tipc_send_group_anycast+0x9bb/0xc80 net/tipc/socket.c:972 > __tipc_sendmsg+0x12b1/0x1d40 net/tipc/socket.c:1309 > tipc_sendmsg+0x50/0x70 net/tipc/socket.c:1272 > 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: 0033:0x457679 > 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:00007f813d748c78 EFLAGS: 00000246 ORIG_RAX: > 000000000000002e > RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457679 > RDX: 0000000000000000 RSI: 00000000200006c0 RDI: 0000000000000005 > RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 00007f813d7496d4 > R13: 00000000004c44dd R14: 00000000004d74c8 R15: 00000000ffffffff > > Allocated by task 10551: > 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] > tipc_group_create+0x152/0xa70 net/tipc/group.c:171 > tipc_sk_join net/tipc/socket.c:2829 [inline] > tipc_setsockopt+0x2d1/0xd70 net/tipc/socket.c:2944 > __sys_setsockopt+0x1ba/0x3c0 net/socket.c:1902 > __do_sys_setsockopt net/socket.c:1913 [inline] > __se_sys_setsockopt net/socket.c:1910 [inline] > __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1910 > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > Freed by task 10567: > 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 > tipc_group_delete+0x2e4/0x3f0 net/tipc/group.c:227 > tipc_sk_leave+0x113/0x220 net/tipc/socket.c:2863 > tipc_setsockopt+0x97d/0xd70 net/tipc/socket.c:2947 > __sys_setsockopt+0x1ba/0x3c0 net/socket.c:1902 > __do_sys_setsockopt net/socket.c:1913 [inline] > __se_sys_setsockopt net/socket.c:1910 [inline] > __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1910 > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > The buggy address belongs to the object at ffff8881c59f5000 > which belongs to the cache kmalloc-192 of size 192 The buggy address is > located 0 bytes inside of > 192-byte region [ffff8881c59f5000, ffff8881c59f50c0) The buggy address > belongs to the page: > page:ffffea0007167d40 count:1 mapcount:0 mapping:ffff8881da800040 > index:0x0 > flags: 0x2fffc0000000200(slab) > raw: 02fffc0000000200 ffffea0007160488 ffffea00071aff08 ffff8881da800040 > raw: 0000000000000000 ffff8881c59f5000 0000000100000010 > 0000000000000000 page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8881c59f4f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff8881c59f4f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > ffff8881c59f5000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff8881c59f5080: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > ffff8881c59f5100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > ========================================================== > ======== > > > --- > 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 syzkal...@googlegroups.com. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with > syzbot. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches
