[ 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 '10.128.0.232' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program syzkaller login: [ 30.465791] netlink: 4 bytes leftover after parsing attributes in process `syz-executor403'. [ 30.475651] netlink: 4 bytes leftover after parsing attributes in process `syz-executor403'. executing program [ 30.538122] netlink: 4 bytes leftover after parsing attributes in process `syz-executor403'. [ 30.546762] netlink: 4 bytes leftover after parsing attributes in process `syz-executor403'. executing program [ 30.606816] netlink: 4 bytes leftover after parsing attributes in process `syz-executor403'. [ 30.615691] netlink: 4 bytes leftover after parsing attributes in process `syz-executor403'. executing program [ 30.656838] netlink: 4 bytes leftover after parsing attributes in process `syz-executor403'. [ 30.665660] netlink: 4 bytes leftover after parsing attributes in process `syz-executor403'. executing program [ 30.716624] netlink: 4 bytes leftover after parsing attributes in process `syz-executor403'. [ 30.725420] netlink: 4 bytes leftover after parsing attributes in process `syz-executor403'. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 31.976118] ================================================================== [ 31.983602] BUG: KASAN: use-after-free in ex_handler_refcount+0x164/0x1a0 [ 31.990608] Write of size 4 at addr ffff8880a8ca9418 by task systemd-udevd/8178 [ 31.998049] [ 31.999678] CPU: 1 PID: 8178 Comm: systemd-udevd Not tainted 4.14.287-syzkaller #0 [ 32.007373] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 [ 32.016706] Call Trace: [ 32.019276] dump_stack+0x1b2/0x281 [ 32.022900] print_address_description.cold+0x54/0x1d3 [ 32.028211] kasan_report_error.cold+0x8a/0x191 [ 32.032870] ? ex_handler_refcount+0x164/0x1a0 [ 32.037526] __asan_report_store4_noabort+0x68/0x70 [ 32.042539] ? ex_handler_refcount+0x164/0x1a0 [ 32.047099] ex_handler_refcount+0x164/0x1a0 [ 32.051488] ? ex_handler_clear_fs+0xb0/0xb0 [ 32.055872] fixup_exception+0x8a/0xd0 [ 32.059746] do_trap+0x61/0x250 [ 32.063006] ? do_error_trap+0x1d0/0x2d0 [ 32.067052] do_error_trap+0x132/0x2d0 [ 32.070928] ? math_error+0x2d0/0x2d0 [ 32.074716] ? flags_string.cold+0x1b38/0x6c27 [ 32.079280] ? __mutex_lock+0x360/0x1310 [ 32.083327] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 32.088147] invalid_op+0x1b/0x40 [ 32.091580] RIP: 0010:flags_string.cold+0x1b38/0x6c27 [ 32.096745] RSP: 0018:ffff8880b0637cd0 EFLAGS: 00010296 [ 32.102121] RAX: 0000000000000000 RBX: ffff8880a8ca9418 RCX: ffff8880a8ca9418 [ 32.109383] RDX: 0000000000000004 RSI: 0000000000000003 RDI: 0000000000000001 [ 32.116631] RBP: ffffffff89510660 R08: 0000000000000000 R09: 0000000000000002 [ 32.123898] R10: 0000000000000000 R11: ffff8880b0264480 R12: 0000000000000000 [ 32.131149] R13: ffff88808a802884 R14: ffffed101150055e R15: dffffc0000000000 [ 32.138418] nbd_release+0xf3/0x150 [ 32.142023] ? nbd_ioctl+0xac0/0xac0 [ 32.145721] __blkdev_put+0x5aa/0x800 [ 32.149503] ? revalidate_disk+0x1f0/0x1f0 [ 32.153718] ? locks_remove_file+0x2cd/0x420 [ 32.158103] ? blkdev_put+0x75/0x4c0 [ 32.161792] ? blkdev_put+0x4c0/0x4c0 [ 32.165573] blkdev_close+0x86/0xb0 [ 32.169267] __fput+0x25f/0x7a0 [ 32.172538] task_work_run+0x11f/0x190 [ 32.176417] exit_to_usermode_loop+0x1ad/0x200 [ 32.180978] do_syscall_64+0x4a3/0x640 [ 32.184860] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 32.190034] RIP: 0033:0x7f3f5c240270 [ 32.193718] RSP: 002b:00007fff05073ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 32.201415] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f3f5c240270 [ 32.208660] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 32.215919] RBP: 00007f3f5d0fa710 R08: 0000000000000045 R09: 0000000000000018 [ 32.223169] R10: 0000564f7c1021b8 R11: 0000000000000246 R12: 0000000000000000 [ 32.230417] R13: 0000564f7c101c20 R14: 0000000000000003 R15: 000000000000000e [ 32.237667] [ 32.239270] Allocated by task 8159: [ 32.242891] kasan_kmalloc+0xeb/0x160 [ 32.246690] kmem_cache_alloc_trace+0x131/0x3d0 [ 32.251333] nbd_dev_add+0x7c/0x800 [ 32.254939] nbd_genl_connect+0x3a4/0x13e0 [ 32.259149] genl_family_rcv_msg+0x572/0xb20 [ 32.263529] genl_rcv_msg+0xaf/0x140 [ 32.267229] netlink_rcv_skb+0x125/0x390 [ 32.271264] genl_rcv+0x24/0x40 [ 32.274516] netlink_unicast+0x437/0x610 [ 32.278549] netlink_sendmsg+0x648/0xbc0 [ 32.282581] sock_sendmsg+0xb5/0x100 [ 32.286266] ___sys_sendmsg+0x6c8/0x800 [ 32.290214] __sys_sendmsg+0xa3/0x120 [ 32.293991] SyS_sendmsg+0x27/0x40 [ 32.297506] do_syscall_64+0x1d5/0x640 [ 32.301382] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 32.306556] [ 32.308163] Freed by task 8145: [ 32.311427] kasan_slab_free+0xc3/0x1a0 [ 32.316518] kfree+0xc9/0x250 [ 32.319620] nbd_put.part.0+0x100/0x140 [ 32.323589] nbd_genl_connect+0xcf6/0x13e0 [ 32.327802] genl_family_rcv_msg+0x572/0xb20 [ 32.332194] genl_rcv_msg+0xaf/0x140 [ 32.335902] netlink_rcv_skb+0x125/0x390 [ 32.339966] genl_rcv+0x24/0x40 [ 32.343267] netlink_unicast+0x437/0x610 [ 32.347303] netlink_sendmsg+0x648/0xbc0 [ 32.351350] sock_sendmsg+0xb5/0x100 [ 32.355047] ___sys_sendmsg+0x6c8/0x800 [ 32.359005] __sys_sendmsg+0xa3/0x120 [ 32.362784] SyS_sendmsg+0x27/0x40 [ 32.366300] do_syscall_64+0x1d5/0x640 [ 32.370182] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 32.375350] [ 32.376960] The buggy address belongs to the object at ffff8880a8ca9340 [ 32.376960] which belongs to the cache kmalloc-512 of size 512 [ 32.389596] The buggy address is located 216 bytes inside of [ 32.389596] 512-byte region [ffff8880a8ca9340, ffff8880a8ca9540) [ 32.401543] The buggy address belongs to the page: [ 32.406462] page:ffffea0002a32a40 count:1 mapcount:0 mapping:ffff8880a8ca90c0 index:0x0 [ 32.414694] flags: 0xfff00000000100(slab) [ 32.418831] raw: 00fff00000000100 ffff8880a8ca90c0 0000000000000000 0000000100000006 [ 32.426700] raw: ffffea0002a329a0 ffffea0002a32ae0 ffff88813fe74940 0000000000000000 [ 32.434569] page dumped because: kasan: bad access detected [ 32.440268] [ 32.441882] Memory state around the buggy address: [ 32.446796] ffff8880a8ca9300: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 32.454129] ffff8880a8ca9380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 32.461463] >ffff8880a8ca9400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 32.468811] ^ [ 32.473547] ffff8880a8ca9480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 32.480883] ffff8880a8ca9500: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 32.488403] ================================================================== [ 32.495742] Disabling lock debugging due to kernel taint [ 32.503857] Kernel panic - not syncing: panic_on_warn set ... [ 32.503857] [ 32.511579] CPU: 0 PID: 8178 Comm: systemd-udevd Tainted: G B 4.14.287-syzkaller #0 [ 32.520491] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 [ 32.530099] Call Trace: [ 32.532678] dump_stack+0x1b2/0x281 [ 32.536291] panic+0x1f9/0x42d [ 32.539479] ? add_taint.cold+0x16/0x16 [ 32.543476] ? ___preempt_schedule+0x16/0x18 [ 32.547902] kasan_end_report+0x43/0x49 [ 32.551882] kasan_report_error.cold+0xa7/0x191 [ 32.556531] ? ex_handler_refcount+0x164/0x1a0 [ 32.561142] __asan_report_store4_noabort+0x68/0x70 [ 32.566158] ? ex_handler_refcount+0x164/0x1a0 [ 32.570721] ex_handler_refcount+0x164/0x1a0 [ 32.575199] ? ex_handler_clear_fs+0xb0/0xb0 [ 32.579586] fixup_exception+0x8a/0xd0 [ 32.583451] do_trap+0x61/0x250 [ 32.586706] ? do_error_trap+0x1d0/0x2d0 [ 32.590740] do_error_trap+0x132/0x2d0 [ 32.594604] ? math_error+0x2d0/0x2d0 [ 32.598398] ? flags_string.cold+0x1b38/0x6c27 [ 32.602965] ? __mutex_lock+0x360/0x1310 [ 32.607005] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 32.611826] invalid_op+0x1b/0x40 [ 32.615259] RIP: 0010:flags_string.cold+0x1b38/0x6c27 [ 32.620421] RSP: 0018:ffff8880b0637cd0 EFLAGS: 00010296 [ 32.625767] RAX: 0000000000000000 RBX: ffff8880a8ca9418 RCX: ffff8880a8ca9418 [ 32.633171] RDX: 0000000000000004 RSI: 0000000000000003 RDI: 0000000000000001 [ 32.640431] RBP: ffffffff89510660 R08: 0000000000000000 R09: 0000000000000002 [ 32.647682] R10: 0000000000000000 R11: ffff8880b0264480 R12: 0000000000000000 [ 32.654937] R13: ffff88808a802884 R14: ffffed101150055e R15: dffffc0000000000 [ 32.662204] nbd_release+0xf3/0x150 [ 32.665811] ? nbd_ioctl+0xac0/0xac0 [ 32.669501] __blkdev_put+0x5aa/0x800 [ 32.673279] ? revalidate_disk+0x1f0/0x1f0 [ 32.677487] ? locks_remove_file+0x2cd/0x420 [ 32.681870] ? blkdev_put+0x75/0x4c0 [ 32.685560] ? blkdev_put+0x4c0/0x4c0 [ 32.689337] blkdev_close+0x86/0xb0 [ 32.692939] __fput+0x25f/0x7a0 [ 32.696201] task_work_run+0x11f/0x190 [ 32.700068] exit_to_usermode_loop+0x1ad/0x200 [ 32.704628] do_syscall_64+0x4a3/0x640 [ 32.708493] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 32.713656] RIP: 0033:0x7f3f5c240270 [ 32.717343] RSP: 002b:00007fff05073ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 32.725026] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f3f5c240270 [ 32.732270] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 32.739516] RBP: 00007f3f5d0fa710 R08: 0000000000000045 R09: 0000000000000018 [ 32.746760] R10: 0000564f7c1021b8 R11: 0000000000000246 R12: 0000000000000000 [ 32.754004] R13: 0000564f7c101c20 R14: 0000000000000003 R15: 000000000000000e [ 32.761445] Kernel Offset: disabled [ 32.765054] Rebooting in 86400 seconds..