[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.73' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 51.521288] ================================================================== [ 51.528925] BUG: KASAN: use-after-free in ex_handler_refcount+0x18f/0x1c0 [ 51.535834] Write of size 4 at addr ffff8880b072d398 by task systemd-udevd/9726 [ 51.543254] [ 51.544873] CPU: 1 PID: 9726 Comm: systemd-udevd Not tainted 4.19.211-syzkaller #0 [ 51.552556] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.561886] Call Trace: [ 51.564457] dump_stack+0x1fc/0x2ef [ 51.568068] print_address_description.cold+0x54/0x219 [ 51.573436] kasan_report_error.cold+0x8a/0x1b9 [ 51.578086] ? ex_handler_refcount+0x18f/0x1c0 [ 51.582649] __asan_report_store4_noabort+0x88/0x90 [ 51.587648] ? notify_die+0x21/0x170 [ 51.591341] ? ex_handler_refcount+0x18f/0x1c0 [ 51.595901] ex_handler_refcount+0x18f/0x1c0 [ 51.600286] ? ex_handler_clear_fs+0xb0/0xb0 [ 51.604681] fixup_exception+0x8a/0xd0 [ 51.608551] do_trap+0x61/0x250 [ 51.611818] ? do_error_trap+0x212/0x310 [ 51.615861] do_error_trap+0x15d/0x310 [ 51.619727] ? math_error+0x310/0x310 [ 51.623511] ? __noinstr_text_end+0x243b/0x7813 [ 51.628163] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 51.632987] invalid_op+0x14/0x20 [ 51.636421] RIP: 0010:__noinstr_text_end+0x243b/0x7813 [ 51.641678] Code: 0f 0b 48 8d 4b 50 0f 0b 48 8d 4b 08 0f 0b 48 8d 4d 08 0f 0b 48 8d 8d 08 02 00 00 0f 0b 48 8d 0b 0f 0b 48 8d 0b 0f 0b 48 8d 0b <0f> 0b 48 8d 4d 00 0f 0b 49 8d 0c 24 0f 0b 48 8d 8b c0 00 00 00 0f [ 51.660559] RSP: 0018:ffff888098d97cd8 EFLAGS: 00010296 [ 51.665909] RAX: 0000000000000000 RBX: ffff8880b072d398 RCX: ffff8880b072d398 [ 51.673161] RDX: 0000000000000004 RSI: 0000000000000004 RDI: 0000000000000001 [ 51.680408] RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff14b7985 [ 51.687675] R10: ffffffff8a5bcc2b R11: 0000000000000000 R12: ffffffff8a5bcc20 [ 51.694924] R13: 0000000000000000 R14: 1ffff1101144a565 R15: dffffc0000000000 [ 51.702195] ? refcount_dec_and_mutex_lock+0x4a/0x80 [ 51.707278] nbd_release+0x108/0x170 [ 51.710990] ? nbd_queue_rq+0xe60/0xe60 [ 51.714962] __blkdev_put+0x636/0x870 [ 51.718759] ? fsync_bdev+0xc0/0xc0 [ 51.722371] ? locks_remove_file+0x2cd/0x450 [ 51.726763] ? blkdev_put+0x85/0x520 [ 51.730455] ? blkdev_put+0x520/0x520 [ 51.734236] blkdev_close+0x86/0xb0 [ 51.737849] __fput+0x2ce/0x890 [ 51.741117] task_work_run+0x148/0x1c0 [ 51.744987] exit_to_usermode_loop+0x251/0x2a0 [ 51.749553] do_syscall_64+0x538/0x620 [ 51.753423] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 51.758591] RIP: 0033:0x7f455a65e270 [ 51.762286] Code: 73 01 c3 48 8b 0d 38 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 59 c1 20 00 00 75 10 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ee fb ff ff 48 89 04 24 [ 51.781168] RSP: 002b:00007ffd5df68338 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 51.788856] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f455a65e270 [ 51.796103] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 51.803363] RBP: 00007f455b518710 R08: 00005616edf8fc40 R09: 0000000000000018 [ 51.810619] R10: 00005616edf8f1b8 R11: 0000000000000246 R12: 0000000000000000 [ 51.817879] R13: 00005616edf8a6e0 R14: 0000000000000003 R15: 000000000000000e [ 51.825147] [ 51.826759] Allocated by task 9711: [ 51.830377] kmem_cache_alloc_trace+0x12f/0x380 [ 51.835036] nbd_dev_add+0x44/0x890 [ 51.838646] nbd_genl_connect+0x4cc/0x1630 [ 51.842862] genl_family_rcv_msg+0x642/0xc40 [ 51.847248] genl_rcv_msg+0xbf/0x160 [ 51.850939] netlink_rcv_skb+0x160/0x440 [ 51.854978] genl_rcv+0x24/0x40 [ 51.858236] netlink_unicast+0x4d5/0x690 [ 51.862275] netlink_sendmsg+0x6c3/0xc50 [ 51.866328] sock_sendmsg+0xc3/0x120 [ 51.870019] ___sys_sendmsg+0x7bb/0x8e0 [ 51.873972] __x64_sys_sendmsg+0x132/0x220 [ 51.878186] do_syscall_64+0xf9/0x620 [ 51.881966] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 51.887128] [ 51.888732] Freed by task 9718: [ 51.891995] kfree+0xcc/0x210 [ 51.895081] nbd_put.part.0+0xfe/0x140 [ 51.898946] nbd_genl_connect+0x120e/0x1630 [ 51.903245] genl_family_rcv_msg+0x642/0xc40 [ 51.907630] genl_rcv_msg+0xbf/0x160 [ 51.911321] netlink_rcv_skb+0x160/0x440 [ 51.915358] genl_rcv+0x24/0x40 [ 51.918632] netlink_unicast+0x4d5/0x690 [ 51.922671] netlink_sendmsg+0x6c3/0xc50 [ 51.926726] sock_sendmsg+0xc3/0x120 [ 51.930421] ___sys_sendmsg+0x7bb/0x8e0 [ 51.934370] __x64_sys_sendmsg+0x132/0x220 [ 51.938584] do_syscall_64+0xf9/0x620 [ 51.942372] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 51.947795] [ 51.949404] The buggy address belongs to the object at ffff8880b072d2c0 [ 51.949404] which belongs to the cache kmalloc-512 of size 512 [ 51.962049] The buggy address is located 216 bytes inside of [ 51.962049] 512-byte region [ffff8880b072d2c0, ffff8880b072d4c0) [ 51.973898] The buggy address belongs to the page: [ 51.978805] page:ffffea0002c1cb40 count:1 mapcount:0 mapping:ffff88813bff0940 index:0x0 [ 51.986924] flags: 0xfff00000000100(slab) [ 51.991054] raw: 00fff00000000100 ffffea0002636d08 ffffea000266fac8 ffff88813bff0940 [ 51.998915] raw: 0000000000000000 ffff8880b072d040 0000000100000006 0000000000000000 [ 52.006772] page dumped because: kasan: bad access detected [ 52.012458] [ 52.014064] Memory state around the buggy address: executing program [ 52.018971] ffff8880b072d280: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 52.026311] ffff8880b072d300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 52.033649] >ffff8880b072d380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 52.040983] ^ [ 52.045108] ffff8880b072d400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 52.052445] ffff8880b072d480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 52.059780] ================================================================== [ 52.067117] Disabling lock debugging due to kernel taint [ 52.077902] Kernel panic - not syncing: panic_on_warn set ... [ 52.077902] [ 52.085298] CPU: 0 PID: 9726 Comm: systemd-udevd Tainted: G B 4.19.211-syzkaller #0 [ 52.094397] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.103747] Call Trace: [ 52.106338] dump_stack+0x1fc/0x2ef [ 52.109959] panic+0x26a/0x50e [ 52.113143] ? __warn_printk+0xf3/0xf3 [ 52.117016] ? preempt_schedule_common+0x45/0xc0 [ 52.122113] ? ___preempt_schedule+0x16/0x18 [ 52.126513] ? trace_hardirqs_on+0x55/0x210 [ 52.130815] kasan_end_report+0x43/0x49 [ 52.134769] kasan_report_error.cold+0xa7/0x1b9 [ 52.139422] ? ex_handler_refcount+0x18f/0x1c0 [ 52.143985] __asan_report_store4_noabort+0x88/0x90 [ 52.148983] ? notify_die+0x21/0x170 [ 52.152678] ? ex_handler_refcount+0x18f/0x1c0 [ 52.157236] ex_handler_refcount+0x18f/0x1c0 [ 52.161624] ? ex_handler_clear_fs+0xb0/0xb0 [ 52.166012] fixup_exception+0x8a/0xd0 [ 52.169878] do_trap+0x61/0x250 [ 52.173138] ? do_error_trap+0x212/0x310 [ 52.177177] do_error_trap+0x15d/0x310 [ 52.181044] ? math_error+0x310/0x310 [ 52.184831] ? __noinstr_text_end+0x243b/0x7813 [ 52.189485] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 52.194307] invalid_op+0x14/0x20 [ 52.197740] RIP: 0010:__noinstr_text_end+0x243b/0x7813 [ 52.202996] Code: 0f 0b 48 8d 4b 50 0f 0b 48 8d 4b 08 0f 0b 48 8d 4d 08 0f 0b 48 8d 8d 08 02 00 00 0f 0b 48 8d 0b 0f 0b 48 8d 0b 0f 0b 48 8d 0b <0f> 0b 48 8d 4d 00 0f 0b 49 8d 0c 24 0f 0b 48 8d 8b c0 00 00 00 0f [ 52.221878] RSP: 0018:ffff888098d97cd8 EFLAGS: 00010296 [ 52.227221] RAX: 0000000000000000 RBX: ffff8880b072d398 RCX: ffff8880b072d398 [ 52.234471] RDX: 0000000000000004 RSI: 0000000000000004 RDI: 0000000000000001 [ 52.241722] RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff14b7985 [ 52.248971] R10: ffffffff8a5bcc2b R11: 0000000000000000 R12: ffffffff8a5bcc20 [ 52.256223] R13: 0000000000000000 R14: 1ffff1101144a565 R15: dffffc0000000000 [ 52.263494] ? refcount_dec_and_mutex_lock+0x4a/0x80 [ 52.268580] nbd_release+0x108/0x170 [ 52.272275] ? nbd_queue_rq+0xe60/0xe60 [ 52.276227] __blkdev_put+0x636/0x870 [ 52.280008] ? fsync_bdev+0xc0/0xc0 [ 52.283623] ? locks_remove_file+0x2cd/0x450 [ 52.288014] ? blkdev_put+0x85/0x520 [ 52.291706] ? blkdev_put+0x520/0x520 [ 52.295483] blkdev_close+0x86/0xb0 [ 52.299098] __fput+0x2ce/0x890 [ 52.302375] task_work_run+0x148/0x1c0 [ 52.306251] exit_to_usermode_loop+0x251/0x2a0 [ 52.310812] do_syscall_64+0x538/0x620 [ 52.314681] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 52.319849] RIP: 0033:0x7f455a65e270 [ 52.323540] Code: 73 01 c3 48 8b 0d 38 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 59 c1 20 00 00 75 10 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ee fb ff ff 48 89 04 24 [ 52.342420] RSP: 002b:00007ffd5df68338 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 52.350108] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f455a65e270 [ 52.357355] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 52.364607] RBP: 00007f455b518710 R08: 00005616edf8fc40 R09: 0000000000000018 [ 52.371858] R10: 00005616edf8f1b8 R11: 0000000000000246 R12: 0000000000000000 [ 52.379105] R13: 00005616edf8a6e0 R14: 0000000000000003 R15: 000000000000000e [ 52.386541] Kernel Offset: disabled [ 52.390151] Rebooting in 86400 seconds..