Warning: Permanently added '10.128.0.46' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 37.216467] netlink: 4 bytes leftover after parsing attributes in process `syz-executor832'. [ 37.225367] netlink: 4 bytes leftover after parsing attributes in process `syz-executor832'. [ 37.235636] netlink: 4 bytes leftover after parsing attributes in process `syz-executor832'. [ 37.245277] netlink: 4 bytes leftover after parsing attributes in process `syz-executor832'. [ 37.254670] netlink: 4 bytes leftover after parsing attributes in process `syz-executor832'. [ 37.263920] netlink: 4 bytes leftover after parsing attributes in process `syz-executor832'. [ 37.273289] netlink: 4 bytes leftover after parsing attributes in process `syz-executor832'. [ 37.288451] netlink: 4 bytes leftover after parsing attributes in process `syz-executor832'. [ 37.297752] netlink: 4 bytes leftover after parsing attributes in process `syz-executor832'. [ 37.306592] netlink: 4 bytes leftover after parsing attributes in process `syz-executor832'. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 37.993829] ================================================================== [ 38.001329] BUG: KASAN: use-after-free in refcount_dec_not_one+0x71/0x1d0 [ 38.008314] Read of size 4 at addr ffff8880ab7ff8d8 by task systemd-udevd/8181 [ 38.015667] [ 38.017283] CPU: 1 PID: 8181 Comm: systemd-udevd Not tainted 4.19.191-syzkaller #0 [ 38.025003] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.034343] Call Trace: [ 38.036923] dump_stack+0x1fc/0x2ef [ 38.040541] print_address_description.cold+0x54/0x219 [ 38.045824] kasan_report_error.cold+0x8a/0x1b9 [ 38.050592] ? refcount_dec_not_one+0x71/0x1d0 [ 38.055191] kasan_report+0x8f/0xa0 [ 38.058818] ? refcount_dec_not_one+0x71/0x1d0 [ 38.063389] refcount_dec_not_one+0x71/0x1d0 [ 38.067875] ? refcount_dec_and_test_checked+0x20/0x20 [ 38.073141] ? nbd_config_put+0x5da/0x870 [ 38.077290] refcount_dec_and_mutex_lock+0x1c/0x80 [ 38.082232] nbd_release+0x108/0x170 [ 38.085949] ? nbd_queue_rq+0xe60/0xe60 [ 38.089918] __blkdev_put+0x636/0x870 [ 38.093738] ? fsync_bdev+0xc0/0xc0 [ 38.097347] ? locks_remove_file+0x2cd/0x450 [ 38.101741] ? blkdev_put+0x85/0x520 [ 38.105449] ? blkdev_put+0x520/0x520 [ 38.109232] blkdev_close+0x86/0xb0 [ 38.112856] __fput+0x2ce/0x890 [ 38.116127] task_work_run+0x148/0x1c0 [ 38.120011] exit_to_usermode_loop+0x251/0x2a0 [ 38.124580] do_syscall_64+0x538/0x620 [ 38.128453] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 38.133625] RIP: 0033:0x7fa8d5e0e270 [ 38.137407] 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 [ 38.156311] RSP: 002b:00007fffae034c48 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 38.164021] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007fa8d5e0e270 [ 38.171364] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 38.178617] RBP: 00007fa8d6cc8710 R08: 000055c3551a4eb0 R09: 0000000000000008 [ 38.185968] R10: 000055c3551a4c98 R11: 0000000000000246 R12: 0000000000000000 [ 38.193237] R13: 000055c3551a3880 R14: 0000000000000003 R15: 000000000000000e [ 38.200510] [ 38.202207] Allocated by task 8178: [ 38.205835] kmem_cache_alloc_trace+0x12f/0x380 [ 38.210499] nbd_dev_add+0x44/0x890 [ 38.214117] nbd_genl_connect+0x4cc/0x1630 [ 38.218336] genl_family_rcv_msg+0x642/0xc40 [ 38.222744] genl_rcv_msg+0xbf/0x160 [ 38.226442] netlink_rcv_skb+0x160/0x440 [ 38.230497] genl_rcv+0x24/0x40 [ 38.233757] netlink_unicast+0x4d5/0x690 [ 38.237807] netlink_sendmsg+0x6bb/0xc40 [ 38.241853] sock_sendmsg+0xc3/0x120 [ 38.245562] ___sys_sendmsg+0x7bb/0x8e0 [ 38.249532] __x64_sys_sendmsg+0x132/0x220 [ 38.253752] do_syscall_64+0xf9/0x620 [ 38.257546] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 38.262712] [ 38.264320] Freed by task 8181: [ 38.267582] kfree+0xcc/0x210 [ 38.270701] nbd_put.part.0+0xfe/0x140 [ 38.274579] nbd_config_put+0x6a0/0x870 [ 38.278546] nbd_release+0xf4/0x170 [ 38.282164] __blkdev_put+0x636/0x870 [ 38.285961] blkdev_close+0x86/0xb0 [ 38.289573] __fput+0x2ce/0x890 [ 38.292837] task_work_run+0x148/0x1c0 [ 38.296724] exit_to_usermode_loop+0x251/0x2a0 [ 38.301293] do_syscall_64+0x538/0x620 [ 38.305193] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 38.310377] [ 38.311989] The buggy address belongs to the object at ffff8880ab7ff800 [ 38.311989] which belongs to the cache kmalloc-512 of size 512 [ 38.324734] The buggy address is located 216 bytes inside of [ 38.324734] 512-byte region [ffff8880ab7ff800, ffff8880ab7ffa00) [ 38.336598] The buggy address belongs to the page: [ 38.341520] page:ffffea0002adffc0 count:1 mapcount:0 mapping:ffff88813bff0940 index:0x0 [ 38.349652] flags: 0xfff00000000100(slab) [ 38.353804] raw: 00fff00000000100 ffffea0002cf0a08 ffffea0002adb6c8 ffff88813bff0940 [ 38.361698] raw: 0000000000000000 ffff8880ab7ff080 0000000100000006 0000000000000000 [ 38.369574] page dumped because: kasan: bad access detected [ 38.375280] [ 38.376895] Memory state around the buggy address: [ 38.381809] ffff8880ab7ff780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 38.389175] ffff8880ab7ff800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.396537] >ffff8880ab7ff880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.403891] ^ [ 38.410109] ffff8880ab7ff900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.417471] ffff8880ab7ff980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.424816] ================================================================== [ 38.432177] Disabling lock debugging due to kernel taint [ 38.441647] Kernel panic - not syncing: panic_on_warn set ... [ 38.441647] [ 38.449037] CPU: 1 PID: 8181 Comm: systemd-udevd Tainted: G B 4.19.191-syzkaller #0 [ 38.458139] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.467507] Call Trace: [ 38.470112] dump_stack+0x1fc/0x2ef [ 38.473810] panic+0x26a/0x50e [ 38.476998] ? __warn_printk+0xf3/0xf3 [ 38.480875] ? preempt_schedule_common+0x45/0xc0 [ 38.485629] ? ___preempt_schedule+0x16/0x18 [ 38.490019] ? trace_hardirqs_on+0x55/0x210 [ 38.494383] kasan_end_report+0x43/0x49 [ 38.498346] kasan_report_error.cold+0xa7/0x1b9 [ 38.503016] ? refcount_dec_not_one+0x71/0x1d0 [ 38.507584] kasan_report+0x8f/0xa0 [ 38.511200] ? refcount_dec_not_one+0x71/0x1d0 [ 38.515763] refcount_dec_not_one+0x71/0x1d0 [ 38.520172] ? refcount_dec_and_test_checked+0x20/0x20 [ 38.525447] ? nbd_config_put+0x5da/0x870 [ 38.529576] refcount_dec_and_mutex_lock+0x1c/0x80 [ 38.534500] nbd_release+0x108/0x170 [ 38.538205] ? nbd_queue_rq+0xe60/0xe60 [ 38.542190] __blkdev_put+0x636/0x870 [ 38.545986] ? fsync_bdev+0xc0/0xc0 [ 38.549604] ? locks_remove_file+0x2cd/0x450 [ 38.553996] ? blkdev_put+0x85/0x520 [ 38.557709] ? blkdev_put+0x520/0x520 [ 38.561594] blkdev_close+0x86/0xb0 [ 38.565217] __fput+0x2ce/0x890 [ 38.568482] task_work_run+0x148/0x1c0 [ 38.572370] exit_to_usermode_loop+0x251/0x2a0 [ 38.576935] do_syscall_64+0x538/0x620 [ 38.580825] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 38.586020] RIP: 0033:0x7fa8d5e0e270 [ 38.589726] 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 [ 38.608616] RSP: 002b:00007fffae034c48 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 38.616329] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007fa8d5e0e270 [ 38.623581] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 38.630855] RBP: 00007fa8d6cc8710 R08: 000055c3551a4eb0 R09: 0000000000000008 [ 38.638121] R10: 000055c3551a4c98 R11: 0000000000000246 R12: 0000000000000000 [ 38.645384] R13: 000055c3551a3880 R14: 0000000000000003 R15: 000000000000000e [ 38.653311] Kernel Offset: disabled [ 38.656944] Rebooting in 86400 seconds..