[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.44' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program syzkaller login: [ 28.120656] netlink: 36 bytes leftover after parsing attributes in process `syz-executor296'. [ 28.130013] netlink: 4 bytes leftover after parsing attributes in process `syz-executor296'. executing program [ 28.192782] netlink: 36 bytes leftover after parsing attributes in process `syz-executor296'. [ 28.201955] netlink: 4 bytes leftover after parsing attributes in process `syz-executor296'. executing program [ 28.241305] netlink: 36 bytes leftover after parsing attributes in process `syz-executor296'. [ 28.250945] netlink: 4 bytes leftover after parsing attributes in process `syz-executor296'. executing program [ 28.291519] netlink: 36 bytes leftover after parsing attributes in process `syz-executor296'. [ 28.301183] netlink: 4 bytes leftover after parsing attributes in process `syz-executor296'. executing program [ 28.361490] netlink: 36 bytes leftover after parsing attributes in process `syz-executor296'. [ 28.370311] netlink: 4 bytes leftover after parsing attributes in process `syz-executor296'. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 29.610331] ================================================================== [ 29.617824] BUG: KASAN: use-after-free in ex_handler_refcount+0x164/0x1a0 [ 29.624746] Write of size 4 at addr ffff8880a91cb8d8 by task systemd-udevd/8149 [ 29.632174] [ 29.633780] CPU: 1 PID: 8149 Comm: systemd-udevd Not tainted 4.14.284-syzkaller #0 [ 29.641463] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.650812] Call Trace: [ 29.653383] dump_stack+0x1b2/0x281 [ 29.657011] print_address_description.cold+0x54/0x1d3 [ 29.662271] kasan_report_error.cold+0x8a/0x191 [ 29.666925] ? ex_handler_refcount+0x164/0x1a0 [ 29.671482] __asan_report_store4_noabort+0x68/0x70 [ 29.676473] ? ex_handler_refcount+0x164/0x1a0 [ 29.681465] ex_handler_refcount+0x164/0x1a0 [ 29.685862] ? ex_handler_clear_fs+0xb0/0xb0 [ 29.690242] fixup_exception+0x8a/0xd0 [ 29.694108] do_trap+0x61/0x250 [ 29.697362] ? do_error_trap+0x1d0/0x2d0 [ 29.701397] do_error_trap+0x132/0x2d0 [ 29.705259] ? math_error+0x2d0/0x2d0 [ 29.709034] ? flags_string.cold+0x1b38/0x6bf7 [ 29.713604] ? __mutex_lock+0x360/0x1310 [ 29.717653] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.722498] invalid_op+0x1b/0x40 [ 29.725942] RIP: 0010:flags_string.cold+0x1b38/0x6bf7 [ 29.731104] RSP: 0018:ffff8880b1cb7cd0 EFLAGS: 00010296 [ 29.736444] RAX: 0000000000000000 RBX: ffff8880a91cb8d8 RCX: ffff8880a91cb8d8 [ 29.743706] RDX: 0000000000000004 RSI: 0000000000000003 RDI: 0000000000000001 [ 29.750960] RBP: ffffffff89514180 R08: 0000000000000000 R09: 0000000000000002 [ 29.758214] R10: 0000000000000000 R11: ffff888096c2e5c0 R12: 0000000000000000 [ 29.765464] R13: ffff88808a41b144 R14: ffffed1011483676 R15: dffffc0000000000 [ 29.772731] nbd_release+0xf3/0x150 [ 29.776340] ? nbd_ioctl+0xac0/0xac0 [ 29.780034] __blkdev_put+0x5aa/0x800 [ 29.783813] ? revalidate_disk+0x1f0/0x1f0 [ 29.788025] ? locks_remove_file+0x2cd/0x420 [ 29.792409] ? blkdev_put+0x75/0x4c0 [ 29.796099] ? blkdev_put+0x4c0/0x4c0 [ 29.799875] blkdev_close+0x86/0xb0 [ 29.803483] __fput+0x25f/0x7a0 [ 29.806739] task_work_run+0x11f/0x190 [ 29.810616] exit_to_usermode_loop+0x1ad/0x200 [ 29.815177] do_syscall_64+0x4a3/0x640 [ 29.819043] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.824208] RIP: 0033:0x7f1cd8fcb270 [ 29.827897] RSP: 002b:00007ffe265980a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 29.835581] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f1cd8fcb270 [ 29.842929] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 29.850178] RBP: 00007f1cd9e85710 R08: 0000563ed7189f40 R09: 0000000000000018 [ 29.857424] R10: 0000563ed7176e38 R11: 0000000000000246 R12: 0000000000000000 [ 29.864676] R13: 0000563ed71856e0 R14: 0000000000000003 R15: 000000000000000e [ 29.871933] [ 29.873536] Allocated by task 8139: [ 29.877208] kasan_kmalloc+0xeb/0x160 [ 29.880990] kmem_cache_alloc_trace+0x131/0x3d0 [ 29.885634] nbd_dev_add+0x7c/0x800 [ 29.889238] nbd_genl_connect+0x3a4/0x13e0 [ 29.893446] genl_family_rcv_msg+0x572/0xb20 [ 29.897827] genl_rcv_msg+0xaf/0x140 [ 29.901532] netlink_rcv_skb+0x125/0x390 [ 29.905567] genl_rcv+0x24/0x40 [ 29.908820] netlink_unicast+0x437/0x610 [ 29.912867] netlink_sendmsg+0x648/0xbc0 [ 29.916914] sock_sendmsg+0xb5/0x100 [ 29.920603] ___sys_sendmsg+0x6c8/0x800 [ 29.924552] __sys_sendmsg+0xa3/0x120 [ 29.928326] SyS_sendmsg+0x27/0x40 [ 29.931840] do_syscall_64+0x1d5/0x640 [ 29.935712] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.940881] [ 29.942482] Freed by task 8161: [ 29.945737] kasan_slab_free+0xc3/0x1a0 [ 29.949686] kfree+0xc9/0x250 [ 29.952767] nbd_put.part.0+0x100/0x140 [ 29.956717] nbd_genl_connect+0xcf6/0x13e0 [ 29.960933] genl_family_rcv_msg+0x572/0xb20 [ 29.965328] genl_rcv_msg+0xaf/0x140 [ 29.969022] netlink_rcv_skb+0x125/0x390 [ 29.973057] genl_rcv+0x24/0x40 [ 29.976316] netlink_unicast+0x437/0x610 [ 29.980380] netlink_sendmsg+0x648/0xbc0 [ 29.984416] sock_sendmsg+0xb5/0x100 [ 29.988114] ___sys_sendmsg+0x6c8/0x800 [ 29.992070] __sys_sendmsg+0xa3/0x120 [ 29.995842] SyS_sendmsg+0x27/0x40 [ 29.999371] do_syscall_64+0x1d5/0x640 [ 30.003240] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 30.008398] [ 30.010000] The buggy address belongs to the object at ffff8880a91cb800 [ 30.010000] which belongs to the cache kmalloc-512 of size 512 [ 30.022629] The buggy address is located 216 bytes inside of [ 30.022629] 512-byte region [ffff8880a91cb800, ffff8880a91cba00) [ 30.034475] The buggy address belongs to the page: [ 30.039385] page:ffffea0002a472c0 count:1 mapcount:0 mapping:ffff8880a91cb080 index:0x0 [ 30.047510] flags: 0xfff00000000100(slab) [ 30.051644] raw: 00fff00000000100 ffff8880a91cb080 0000000000000000 0000000100000006 [ 30.059513] raw: ffffea0002ac6320 ffffea0002939e60 ffff88813fe74940 0000000000000000 [ 30.067362] page dumped because: kasan: bad access detected [ 30.073179] [ 30.074796] Memory state around the buggy address: [ 30.079702] ffff8880a91cb780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 30.087040] ffff8880a91cb800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.094375] >ffff8880a91cb880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.101815] ^ executing program [ 30.108027] ffff8880a91cb900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.115362] ffff8880a91cb980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.122693] ================================================================== [ 30.130025] Disabling lock debugging due to kernel taint [ 30.139862] Kernel panic - not syncing: panic_on_warn set ... [ 30.139862] [ 30.147228] CPU: 0 PID: 8149 Comm: systemd-udevd Tainted: G B 4.14.284-syzkaller #0 [ 30.156140] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.165484] Call Trace: [ 30.168057] dump_stack+0x1b2/0x281 [ 30.171662] panic+0x1f9/0x42d [ 30.174829] ? add_taint.cold+0x16/0x16 [ 30.178778] ? ___preempt_schedule+0x16/0x18 [ 30.183166] kasan_end_report+0x43/0x49 [ 30.187115] kasan_report_error.cold+0xa7/0x191 [ 30.191758] ? ex_handler_refcount+0x164/0x1a0 [ 30.196331] __asan_report_store4_noabort+0x68/0x70 [ 30.201324] ? ex_handler_refcount+0x164/0x1a0 [ 30.205878] ex_handler_refcount+0x164/0x1a0 [ 30.210262] ? ex_handler_clear_fs+0xb0/0xb0 [ 30.214651] fixup_exception+0x8a/0xd0 [ 30.218520] do_trap+0x61/0x250 [ 30.221784] ? do_error_trap+0x1d0/0x2d0 [ 30.225819] do_error_trap+0x132/0x2d0 [ 30.229696] ? math_error+0x2d0/0x2d0 [ 30.233506] ? flags_string.cold+0x1b38/0x6bf7 [ 30.238076] ? __mutex_lock+0x360/0x1310 [ 30.242114] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.246939] invalid_op+0x1b/0x40 [ 30.250371] RIP: 0010:flags_string.cold+0x1b38/0x6bf7 [ 30.255551] RSP: 0018:ffff8880b1cb7cd0 EFLAGS: 00010296 [ 30.260893] RAX: 0000000000000000 RBX: ffff8880a91cb8d8 RCX: ffff8880a91cb8d8 [ 30.268140] RDX: 0000000000000004 RSI: 0000000000000003 RDI: 0000000000000001 [ 30.275390] RBP: ffffffff89514180 R08: 0000000000000000 R09: 0000000000000002 [ 30.282653] R10: 0000000000000000 R11: ffff888096c2e5c0 R12: 0000000000000000 [ 30.289914] R13: ffff88808a41b144 R14: ffffed1011483676 R15: dffffc0000000000 [ 30.297189] nbd_release+0xf3/0x150 [ 30.300810] ? nbd_ioctl+0xac0/0xac0 [ 30.304501] __blkdev_put+0x5aa/0x800 [ 30.308279] ? revalidate_disk+0x1f0/0x1f0 [ 30.312490] ? locks_remove_file+0x2cd/0x420 [ 30.316874] ? blkdev_put+0x75/0x4c0 [ 30.320561] ? blkdev_put+0x4c0/0x4c0 [ 30.324334] blkdev_close+0x86/0xb0 [ 30.327952] __fput+0x25f/0x7a0 [ 30.331215] task_work_run+0x11f/0x190 [ 30.335089] exit_to_usermode_loop+0x1ad/0x200 [ 30.339643] do_syscall_64+0x4a3/0x640 [ 30.343510] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 30.348674] RIP: 0033:0x7f1cd8fcb270 [ 30.352357] RSP: 002b:00007ffe265980a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 30.360050] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f1cd8fcb270 [ 30.367291] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 30.374546] RBP: 00007f1cd9e85710 R08: 0000563ed7189f40 R09: 0000000000000018 [ 30.381789] R10: 0000563ed7176e38 R11: 0000000000000246 R12: 0000000000000000 [ 30.389034] R13: 0000563ed71856e0 R14: 0000000000000003 R15: 000000000000000e [ 30.396462] Kernel Offset: disabled [ 30.400080] Rebooting in 86400 seconds..