[ 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 '10.128.0.39' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program syzkaller login: [ 27.080340] netlink: 4 bytes leftover after parsing attributes in process `syz-executor169'. executing program [ 27.146144] netlink: 4 bytes leftover after parsing attributes in process `syz-executor169'. executing program [ 27.195162] netlink: 4 bytes leftover after parsing attributes in process `syz-executor169'. executing program [ 27.254627] netlink: 4 bytes leftover after parsing attributes in process `syz-executor169'. executing program executing program [ 27.295192] netlink: 4 bytes leftover after parsing attributes in process `syz-executor169'. [ 27.334798] netlink: 4 bytes leftover after parsing attributes in process `syz-executor169'. executing program [ 27.384597] netlink: 4 bytes leftover after parsing attributes in process `syz-executor169'. executing program [ 27.434953] netlink: 4 bytes leftover after parsing attributes in process `syz-executor169'. executing program [ 27.494714] netlink: 4 bytes leftover after parsing attributes in process `syz-executor169'. executing program [ 27.544601] netlink: 4 bytes leftover after parsing attributes in process `syz-executor169'. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 28.634298] ================================================================== [ 28.641789] BUG: KASAN: use-after-free in ex_handler_refcount+0x164/0x1a0 [ 28.648698] Write of size 4 at addr ffff8880a1b11398 by task systemd-udevd/8169 [ 28.656114] [ 28.657721] CPU: 0 PID: 8169 Comm: systemd-udevd Not tainted 4.14.282-syzkaller #0 [ 28.665572] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.674987] Call Trace: [ 28.677552] dump_stack+0x1b2/0x281 [ 28.681156] print_address_description.cold+0x54/0x1d3 [ 28.686409] kasan_report_error.cold+0x8a/0x191 [ 28.691057] ? ex_handler_refcount+0x164/0x1a0 [ 28.695639] __asan_report_store4_noabort+0x68/0x70 [ 28.700635] ? ex_handler_refcount+0x164/0x1a0 [ 28.705226] ex_handler_refcount+0x164/0x1a0 [ 28.709615] ? ex_handler_clear_fs+0xb0/0xb0 [ 28.714046] fixup_exception+0x8a/0xd0 [ 28.718067] do_trap+0x61/0x250 [ 28.721326] ? do_error_trap+0x1d0/0x2d0 [ 28.725373] do_error_trap+0x132/0x2d0 [ 28.729274] ? math_error+0x2d0/0x2d0 [ 28.733055] ? flags_string.cold+0x1b2c/0x6beb [ 28.737618] ? __mutex_lock+0x360/0x1310 [ 28.741695] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 28.746519] invalid_op+0x1b/0x40 [ 28.749947] RIP: 0010:flags_string.cold+0x1b2c/0x6beb [ 28.755106] RSP: 0018:ffff88809570fcd0 EFLAGS: 00010296 [ 28.760441] RAX: 0000000000000000 RBX: ffff8880a1b11398 RCX: ffff8880a1b11398 [ 28.767684] RDX: 0000000000000004 RSI: 0000000000000003 RDI: 0000000000000001 [ 28.774927] RBP: ffffffff89513cc0 R08: 0000000000000000 R09: 0000000000000002 [ 28.782169] R10: 0000000000000000 R11: ffff8880b07e0240 R12: 0000000000000000 [ 28.789415] R13: ffff88808a811804 R14: ffffed101150234e R15: dffffc0000000000 [ 28.796682] nbd_release+0xf3/0x150 [ 28.800283] ? nbd_queue_rq+0xc50/0xc50 [ 28.804229] __blkdev_put+0x5aa/0x800 [ 28.808019] ? revalidate_disk+0x1f0/0x1f0 [ 28.812228] ? locks_remove_file+0x2cd/0x420 [ 28.816612] ? blkdev_put+0x75/0x4c0 [ 28.820298] ? blkdev_put+0x4c0/0x4c0 [ 28.824070] blkdev_close+0x86/0xb0 [ 28.827691] __fput+0x25f/0x7a0 [ 28.830947] task_work_run+0x11f/0x190 [ 28.835424] exit_to_usermode_loop+0x1ad/0x200 [ 28.839981] do_syscall_64+0x4a3/0x640 [ 28.843856] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 28.849055] RIP: 0033:0x7fac0488d270 [ 28.852740] RSP: 002b:00007ffd698a7558 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 28.860445] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007fac0488d270 [ 28.867689] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 28.874931] RBP: 00007fac05747710 R08: 00005620fd85cf40 R09: 0000000000000018 [ 28.882177] R10: 00005620fd858758 R11: 0000000000000246 R12: 0000000000000000 [ 28.889443] R13: 00005620fd85b880 R14: 0000000000000003 R15: 000000000000000e [ 28.896795] [ 28.898397] Allocated by task 8155: [ 28.902782] kasan_kmalloc+0xeb/0x160 [ 28.906558] kmem_cache_alloc_trace+0x131/0x3d0 [ 28.911220] nbd_dev_add+0x7c/0x800 [ 28.914821] nbd_genl_connect+0x3a4/0x1400 [ 28.919030] genl_family_rcv_msg+0x572/0xb20 [ 28.923409] genl_rcv_msg+0xaf/0x140 [ 28.927096] netlink_rcv_skb+0x125/0x390 [ 28.931142] genl_rcv+0x24/0x40 [ 28.935003] netlink_unicast+0x437/0x610 [ 28.939051] netlink_sendmsg+0x648/0xbc0 [ 28.943088] sock_sendmsg+0xb5/0x100 [ 28.946776] ___sys_sendmsg+0x6c8/0x800 [ 28.950721] __sys_sendmsg+0xa3/0x120 [ 28.954494] SyS_sendmsg+0x27/0x40 [ 28.958008] do_syscall_64+0x1d5/0x640 [ 28.961966] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 28.967125] [ 28.968733] Freed by task 8170: [ 28.971985] kasan_slab_free+0xc3/0x1a0 [ 28.975930] kfree+0xc9/0x250 [ 28.979008] nbd_put.part.0+0x100/0x140 [ 28.982955] nbd_genl_connect+0xfa9/0x1400 [ 28.987174] genl_family_rcv_msg+0x572/0xb20 [ 28.991554] genl_rcv_msg+0xaf/0x140 [ 28.995250] netlink_rcv_skb+0x125/0x390 [ 28.999292] genl_rcv+0x24/0x40 [ 29.002545] netlink_unicast+0x437/0x610 [ 29.006576] netlink_sendmsg+0x648/0xbc0 [ 29.010607] sock_sendmsg+0xb5/0x100 [ 29.014295] ___sys_sendmsg+0x6c8/0x800 [ 29.018246] __sys_sendmsg+0xa3/0x120 [ 29.022028] SyS_sendmsg+0x27/0x40 [ 29.025801] do_syscall_64+0x1d5/0x640 [ 29.030113] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.035272] [ 29.036876] The buggy address belongs to the object at ffff8880a1b112c0 [ 29.036876] which belongs to the cache kmalloc-512 of size 512 [ 29.049515] The buggy address is located 216 bytes inside of [ 29.049515] 512-byte region [ffff8880a1b112c0, ffff8880a1b114c0) [ 29.061379] The buggy address belongs to the page: [ 29.066291] page:ffffea000286c440 count:1 mapcount:0 mapping:ffff8880a1b11040 index:0x0 [ 29.074406] flags: 0xfff00000000100(slab) [ 29.078527] raw: 00fff00000000100 ffff8880a1b11040 0000000000000000 0000000100000006 [ 29.086394] raw: ffffea0002c5f420 ffffea0002becee0 ffff88813fe74940 0000000000000000 [ 29.094245] page dumped because: kasan: bad access detected [ 29.099939] [ 29.101538] Memory state around the buggy address: [ 29.106556] ffff8880a1b11280: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 29.113889] ffff8880a1b11300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.121218] >ffff8880a1b11380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.128546] ^ executing program [ 29.132669] ffff8880a1b11400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.140001] ffff8880a1b11480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 29.147330] ================================================================== [ 29.154676] Disabling lock debugging due to kernel taint [ 29.164984] Kernel panic - not syncing: panic_on_warn set ... [ 29.164984] [ 29.172357] CPU: 1 PID: 8169 Comm: systemd-udevd Tainted: G B 4.14.282-syzkaller #0 [ 29.181264] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.190700] Call Trace: [ 29.193283] dump_stack+0x1b2/0x281 [ 29.196891] panic+0x1f9/0x42d [ 29.200064] ? add_taint.cold+0x16/0x16 [ 29.204246] ? ___preempt_schedule+0x16/0x18 [ 29.208630] kasan_end_report+0x43/0x49 [ 29.212582] kasan_report_error.cold+0xa7/0x191 [ 29.217229] ? ex_handler_refcount+0x164/0x1a0 [ 29.221789] __asan_report_store4_noabort+0x68/0x70 [ 29.226782] ? ex_handler_refcount+0x164/0x1a0 [ 29.231336] ex_handler_refcount+0x164/0x1a0 [ 29.235823] ? ex_handler_clear_fs+0xb0/0xb0 [ 29.240202] fixup_exception+0x8a/0xd0 [ 29.244061] do_trap+0x61/0x250 [ 29.247315] ? do_error_trap+0x1d0/0x2d0 [ 29.251374] do_error_trap+0x132/0x2d0 [ 29.255260] ? math_error+0x2d0/0x2d0 [ 29.259128] ? flags_string.cold+0x1b2c/0x6beb [ 29.263686] ? __mutex_lock+0x360/0x1310 [ 29.267721] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.272536] invalid_op+0x1b/0x40 [ 29.275965] RIP: 0010:flags_string.cold+0x1b2c/0x6beb [ 29.281124] RSP: 0018:ffff88809570fcd0 EFLAGS: 00010296 [ 29.286472] RAX: 0000000000000000 RBX: ffff8880a1b11398 RCX: ffff8880a1b11398 [ 29.293721] RDX: 0000000000000004 RSI: 0000000000000003 RDI: 0000000000000001 [ 29.300965] RBP: ffffffff89513cc0 R08: 0000000000000000 R09: 0000000000000002 [ 29.308218] R10: 0000000000000000 R11: ffff8880b07e0240 R12: 0000000000000000 [ 29.315474] R13: ffff88808a811804 R14: ffffed101150234e R15: dffffc0000000000 [ 29.322730] nbd_release+0xf3/0x150 [ 29.326330] ? nbd_queue_rq+0xc50/0xc50 [ 29.330284] __blkdev_put+0x5aa/0x800 [ 29.334063] ? revalidate_disk+0x1f0/0x1f0 [ 29.338279] ? locks_remove_file+0x2cd/0x420 [ 29.343019] ? blkdev_put+0x75/0x4c0 [ 29.346709] ? blkdev_put+0x4c0/0x4c0 [ 29.350486] blkdev_close+0x86/0xb0 [ 29.354228] __fput+0x25f/0x7a0 [ 29.357488] task_work_run+0x11f/0x190 [ 29.361366] exit_to_usermode_loop+0x1ad/0x200 [ 29.366009] do_syscall_64+0x4a3/0x640 [ 29.369876] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.376002] RIP: 0033:0x7fac0488d270 [ 29.379686] RSP: 002b:00007ffd698a7558 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 29.387828] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007fac0488d270 [ 29.395083] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 29.402329] RBP: 00007fac05747710 R08: 00005620fd85cf40 R09: 0000000000000018 [ 29.409572] R10: 00005620fd858758 R11: 0000000000000246 R12: 0000000000000000 [ 29.416818] R13: 00005620fd85b880 R14: 0000000000000003 R15: 000000000000000e [ 29.424438] Kernel Offset: disabled [ 29.428058] Rebooting in 86400 seconds..