[ 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 '10.128.10.34' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program syzkaller login: [ 28.871962] netlink: 4 bytes leftover after parsing attributes in process `syz-executor824'. executing program [ 28.932829] netlink: 4 bytes leftover after parsing attributes in process `syz-executor824'. executing program [ 28.982945] netlink: 4 bytes leftover after parsing attributes in process `syz-executor824'. executing program [ 29.042093] netlink: 4 bytes leftover after parsing attributes in process `syz-executor824'. executing program [ 29.101783] netlink: 4 bytes leftover after parsing attributes in process `syz-executor824'. executing program [ 29.151970] netlink: 4 bytes leftover after parsing attributes in process `syz-executor824'. executing program [ 29.201591] netlink: 4 bytes leftover after parsing attributes in process `syz-executor824'. executing program executing program [ 29.251954] netlink: 4 bytes leftover after parsing attributes in process `syz-executor824'. [ 29.291741] netlink: 4 bytes leftover after parsing attributes in process `syz-executor824'. executing program executing program [ 29.331834] netlink: 4 bytes leftover after parsing attributes in process `syz-executor824'. 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 [ 31.400503] ================================================================== [ 31.407997] BUG: KASAN: use-after-free in ex_handler_refcount+0x164/0x1a0 [ 31.414901] Write of size 4 at addr ffff8880ae544418 by task systemd-udevd/8334 [ 31.422322] [ 31.423932] CPU: 0 PID: 8334 Comm: systemd-udevd Not tainted 4.14.258-syzkaller #0 [ 31.431623] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.440953] Call Trace: [ 31.443521] dump_stack+0x1b2/0x281 [ 31.447126] print_address_description.cold+0x54/0x1d3 [ 31.452379] kasan_report_error.cold+0x8a/0x191 [ 31.457030] ? ex_handler_refcount+0x164/0x1a0 [ 31.461588] __asan_report_store4_noabort+0x68/0x70 [ 31.466581] ? ex_handler_refcount+0x164/0x1a0 [ 31.471138] ex_handler_refcount+0x164/0x1a0 [ 31.475520] ? ex_handler_clear_fs+0xb0/0xb0 [ 31.479906] fixup_exception+0x8a/0xd0 [ 31.483775] do_trap+0x61/0x250 [ 31.487031] ? do_error_trap+0x1d0/0x2d0 [ 31.491069] do_error_trap+0x132/0x2d0 [ 31.494931] ? math_error+0x2d0/0x2d0 [ 31.498707] ? flags_string.cold+0x1b1b/0x6ad8 [ 31.503266] ? __mutex_lock+0x360/0x1310 [ 31.507305] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 31.512130] invalid_op+0x1b/0x40 [ 31.515561] RIP: 0010:flags_string.cold+0x1b1b/0x6ad8 [ 31.520724] RSP: 0018:ffff8880ac197cd0 EFLAGS: 00010296 [ 31.526064] RAX: 0000000000000000 RBX: ffff8880ae544418 RCX: ffff8880ae544418 [ 31.533312] RDX: 0000000000000004 RSI: 0000000000000003 RDI: 0000000000000001 [ 31.540567] RBP: ffffffff895133e0 R08: 0000000000000000 R09: 0000000000000002 [ 31.547813] R10: 0000000000000000 R11: ffff8880abc220c0 R12: 0000000000000000 [ 31.555060] R13: ffff88808c9540c4 R14: ffffed101192a866 R15: dffffc0000000000 [ 31.562324] nbd_release+0xf3/0x150 [ 31.565928] ? nbd_queue_rq+0xc50/0xc50 [ 31.569878] __blkdev_put+0x5aa/0x800 [ 31.573658] ? revalidate_disk+0x1f0/0x1f0 [ 31.577867] ? locks_remove_file+0x2cd/0x420 [ 31.582252] ? blkdev_put+0x75/0x4c0 [ 31.585944] ? blkdev_put+0x4c0/0x4c0 [ 31.589723] blkdev_close+0x86/0xb0 [ 31.593416] __fput+0x25f/0x7a0 [ 31.596673] task_work_run+0x11f/0x190 [ 31.600538] exit_to_usermode_loop+0x1ad/0x200 [ 31.605100] do_syscall_64+0x4a3/0x640 [ 31.608965] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 31.614162] RIP: 0033:0x7f7d83bd4270 [ 31.617858] RSP: 002b:00007ffe6b8117d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 31.625540] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f7d83bd4270 [ 31.632788] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 31.640034] RBP: 00007f7d84a8e710 R08: 0000000000000045 R09: 0000000000000018 [ 31.647291] R10: 000055f53315cf68 R11: 0000000000000246 R12: 0000000000000000 [ 31.654541] R13: 000055f53315cdd0 R14: 0000000000000003 R15: 000000000000000e [ 31.661880] [ 31.663488] Allocated by task 8295: [ 31.667096] kasan_kmalloc+0xeb/0x160 [ 31.670878] kmem_cache_alloc_trace+0x131/0x3d0 [ 31.675527] nbd_dev_add+0x7c/0x800 [ 31.679129] nbd_genl_connect+0x3a4/0x1400 [ 31.683342] genl_family_rcv_msg+0x572/0xb20 [ 31.687726] genl_rcv_msg+0xaf/0x140 [ 31.691417] netlink_rcv_skb+0x125/0x390 [ 31.695458] genl_rcv+0x24/0x40 [ 31.698713] netlink_unicast+0x437/0x610 [ 31.702752] netlink_sendmsg+0x638/0xb90 [ 31.706792] sock_sendmsg+0xb5/0x100 [ 31.710743] ___sys_sendmsg+0x6c8/0x800 [ 31.714694] __sys_sendmsg+0xa3/0x120 [ 31.718492] SyS_sendmsg+0x27/0x40 [ 31.722008] do_syscall_64+0x1d5/0x640 [ 31.725871] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 31.731029] [ 31.732631] Freed by task 8322: [ 31.735942] kasan_slab_free+0xc3/0x1a0 [ 31.739890] kfree+0xc9/0x250 [ 31.742982] nbd_put.part.0+0x100/0x140 [ 31.746931] nbd_genl_connect+0xfa9/0x1400 [ 31.751142] genl_family_rcv_msg+0x572/0xb20 [ 31.755524] genl_rcv_msg+0xaf/0x140 [ 31.759213] netlink_rcv_skb+0x125/0x390 [ 31.763249] genl_rcv+0x24/0x40 [ 31.766502] netlink_unicast+0x437/0x610 [ 31.770546] netlink_sendmsg+0x638/0xb90 [ 31.774593] sock_sendmsg+0xb5/0x100 [ 31.778284] ___sys_sendmsg+0x6c8/0x800 [ 31.782237] __sys_sendmsg+0xa3/0x120 [ 31.786014] SyS_sendmsg+0x27/0x40 [ 31.789530] do_syscall_64+0x1d5/0x640 [ 31.793391] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 31.798574] [ 31.800183] The buggy address belongs to the object at ffff8880ae544340 [ 31.800183] which belongs to the cache kmalloc-512 of size 512 [ 31.812821] The buggy address is located 216 bytes inside of [ 31.812821] 512-byte region [ffff8880ae544340, ffff8880ae544540) [ 31.824669] The buggy address belongs to the page: [ 31.829578] page:ffffea0002b95100 count:1 mapcount:0 mapping:ffff8880ae5440c0 index:0x0 [ 31.837702] flags: 0xfff00000000100(slab) [ 31.841833] raw: 00fff00000000100 ffff8880ae5440c0 0000000000000000 0000000100000006 [ 31.849692] raw: ffffea00027519e0 ffffea0002c25b60 ffff88813fe74940 0000000000000000 [ 31.857635] page dumped because: kasan: bad access detected [ 31.863344] [ 31.864948] Memory state around the buggy address: [ 31.870034] ffff8880ae544300: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 31.877377] ffff8880ae544380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.884711] >ffff8880ae544400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.892128] ^ [ 31.896257] ffff8880ae544480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.903601] ffff8880ae544500: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 31.910931] ================================================================== [ 31.918266] Disabling lock debugging due to kernel taint [ 31.928412] Kernel panic - not syncing: panic_on_warn set ... [ 31.928412] [ 31.935780] CPU: 1 PID: 8334 Comm: systemd-udevd Tainted: G B 4.14.258-syzkaller #0 [ 31.944780] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.954126] Call Trace: [ 31.956694] dump_stack+0x1b2/0x281 [ 31.960299] panic+0x1f9/0x42d [ 31.963465] ? add_taint.cold+0x16/0x16 [ 31.967414] ? ___preempt_schedule+0x16/0x18 [ 31.971798] kasan_end_report+0x43/0x49 [ 31.975747] kasan_report_error.cold+0xa7/0x191 [ 31.980394] ? ex_handler_refcount+0x164/0x1a0 [ 31.984950] __asan_report_store4_noabort+0x68/0x70 [ 31.989941] ? ex_handler_refcount+0x164/0x1a0 [ 31.994499] ex_handler_refcount+0x164/0x1a0 [ 31.998885] ? ex_handler_clear_fs+0xb0/0xb0 [ 32.003271] fixup_exception+0x8a/0xd0 [ 32.007138] do_trap+0x61/0x250 [ 32.010397] ? do_error_trap+0x1d0/0x2d0 [ 32.014433] do_error_trap+0x132/0x2d0 [ 32.018390] ? math_error+0x2d0/0x2d0 [ 32.022164] ? flags_string.cold+0x1b1b/0x6ad8 [ 32.026725] ? __mutex_lock+0x360/0x1310 [ 32.030761] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 32.035577] invalid_op+0x1b/0x40 [ 32.039001] RIP: 0010:flags_string.cold+0x1b1b/0x6ad8 [ 32.044163] RSP: 0018:ffff8880ac197cd0 EFLAGS: 00010296 [ 32.049502] RAX: 0000000000000000 RBX: ffff8880ae544418 RCX: ffff8880ae544418 [ 32.056746] RDX: 0000000000000004 RSI: 0000000000000003 RDI: 0000000000000001 [ 32.063989] RBP: ffffffff895133e0 R08: 0000000000000000 R09: 0000000000000002 [ 32.071239] R10: 0000000000000000 R11: ffff8880abc220c0 R12: 0000000000000000 [ 32.078487] R13: ffff88808c9540c4 R14: ffffed101192a866 R15: dffffc0000000000 [ 32.085760] nbd_release+0xf3/0x150 [ 32.089367] ? nbd_queue_rq+0xc50/0xc50 [ 32.093316] __blkdev_put+0x5aa/0x800 [ 32.097104] ? revalidate_disk+0x1f0/0x1f0 [ 32.101328] ? locks_remove_file+0x2cd/0x420 [ 32.105722] ? blkdev_put+0x75/0x4c0 [ 32.109410] ? blkdev_put+0x4c0/0x4c0 [ 32.113187] blkdev_close+0x86/0xb0 [ 32.116789] __fput+0x25f/0x7a0 [ 32.120045] task_work_run+0x11f/0x190 [ 32.123907] exit_to_usermode_loop+0x1ad/0x200 [ 32.128465] do_syscall_64+0x4a3/0x640 [ 32.132329] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 32.137493] RIP: 0033:0x7f7d83bd4270 [ 32.141181] RSP: 002b:00007ffe6b8117d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 32.148949] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f7d83bd4270 [ 32.156289] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 32.163552] RBP: 00007f7d84a8e710 R08: 0000000000000045 R09: 0000000000000018 [ 32.170801] R10: 000055f53315cf68 R11: 0000000000000246 R12: 0000000000000000 [ 32.178054] R13: 000055f53315cdd0 R14: 0000000000000003 R15: 000000000000000e [ 32.185391] Kernel Offset: disabled [ 32.189009] Rebooting in 86400 seconds..