Ubuntu 18.04.5 LTS bug-1894780 ttyS0 bug-1894780 login: [ 49.940704] kobject_add_internal failed for :a-0000152 with -EEXIST, don't try to register things with the same name in the same directory. [ 49.942215] BUG: kernel NULL pointer dereference, address: 0000000000000020 [ 49.942928] #PF: supervisor read access in kernel mode [ 49.943502] #PF: error_code(0x0000) - not-present page [ 49.945486] PGD 0 P4D 0 [ 49.945921] Oops: 0000 [#1] SMP NOPTI [ 49.946471] CPU: 0 PID: 1444 Comm: lvm Not tainted 5.4.0-47-generic #51~18.04.1-Ubuntu [ 49.947978] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009)/LXD, BIOS 0.0.0 02/06/2015 [ 49.949430] RIP: 0010:free_percpu+0x120/0x1f0 [ 49.950158] Code: 43 64 48 01 d0 49 39 c4 0f 83 71 ff ff ff 65 8b 05 85 4f 5c 6f 48 8b 15 ee 4e 20 01 48 98 48 8b 3c c2 4c 01 e7 e8 f0 97 02 00 <48> 8b 58 20 48 8b 53 38 e9 48 ff ff ff f3 c3 48 8b 43 38 48 89 45 [ 49.953187] RSP: 0018:ffffbb8c4057f8e8 EFLAGS: 00010046 [ 49.954027] RAX: 0000000000000000 RBX: ffffa052bff36200 RCX: ffffffff91e0a000 [ 49.955235] RDX: ac20a9ee026510df RSI: 66ec86c56441a2ac RDI: 0000000000000000 [ 49.956356] RBP: ffffbb8c4057f918 R08: ffffffffffffffff R09: 00000000000003b0 [ 49.957560] R10: 0000000000001f80 R11: 00000000ffffffff R12: ac20a9ee026510df [ 49.958791] R13: ac21099b45e510df R14: 0000000000000283 R15: 0000000000000008 [ 49.959781] FS: 00007fde2c539900(0000) GS:ffffa052bc800000(0000) knlGS:0000000000000000 [ 49.960843] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 49.961783] CR2: 0000000000000020 CR3: 00000000360de000 CR4: 00000000003406f0 [ 49.962615] Call Trace: [ 49.963029] __kmem_cache_release+0x1a/0x30 [ 49.963522] __kmem_cache_create+0x4f9/0x550 [ 49.964021] ? __kmalloc_node+0x1eb/0x320 [ 49.964488] ? kvmalloc_node+0x31/0x80 [ 49.964980] create_cache+0x120/0x1f0 [ 49.965545] kmem_cache_create_usercopy+0x17d/0x270 [ 49.966345] kmem_cache_create+0x16/0x20 [ 49.966924] dm_bufio_client_create+0x1af/0x3f0 [dm_bufio] [ 49.967717] ? snapshot_map+0x5e0/0x5e0 [dm_snapshot] [ 49.968594] persistent_read_metadata+0x1ed/0x500 [dm_snapshot] [ 49.969753] ? _cond_resched+0x19/0x40 [ 49.970455] snapshot_ctr+0x79e/0x910 [dm_snapshot] [ 49.971797] dm_table_add_target+0x18d/0x370 [ 49.972515] table_load+0x12a/0x370 [ 49.973286] ctl_ioctl+0x1e2/0x590 [ 49.974043] ? retrieve_status+0x1c0/0x1c0 [ 49.975430] dm_ctl_ioctl+0xe/0x20 [ 49.975907] do_vfs_ioctl+0xa9/0x640 [ 49.976460] ? ksys_semctl.constprop.19+0xf7/0x190 [ 49.977221] ksys_ioctl+0x75/0x80 [ 49.977749] __x64_sys_ioctl+0x1a/0x20 [ 49.978399] do_syscall_64+0x57/0x190 [ 49.979118] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.980285] RIP: 0033:0x7fde2b0a76d7 [ 49.981269] Code: b3 66 90 48 8b 05 b1 47 2d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 81 47 2d 00 f7 d8 64 89 01 48 [ 49.985361] RSP: 002b:00007ffe3e863f68 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 49.987292] RAX: ffffffffffffffda RBX: 000055b346a6f72c RCX: 00007fde2b0a76d7 [ 49.989021] RDX: 000055b347969530 RSI: 00000000c138fd09 RDI: 0000000000000006 [ 49.990241] RBP: 00007ffe3e864020 R08: 00007fde2b61c120 R09: 00007ffe3e863dd0 [ 49.991412] R10: 000055b3479695e0 R11: 0000000000000202 R12: 00007fde2b61b4e6 [ 49.993264] R13: 00007fde2b61b4e6 R14: 00007fde2b61b4e6 R15: 00007fde2b61b4e6 [ 49.994802] Modules linked in: dm_snapshot dm_bufio isofs nls_iso8859_1 kvm_amd ccp kvm joydev input_leds serio_raw lpc_ich vmw_vsock_virtio_transport vmw_vsock_virtio_transport_common 9pnet_virtio vsock 9pnet virtio_input mac_hid qemu_fw_cfg sch_fq_codel ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi virtio_rng ip_tables x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel crypto_simd virtio_gpu psmouse ttm cryptd glue_helper drm_kms_helper ahci syscopyarea sysfillrect virtio_net sysimgblt net_failover fb_sys_fops libahci failover drm virtio_scsi [ 50.008892] CR2: 0000000000000020 [ 50.009860] ---[ end trace b82febc1334f3eab ]--- [ 50.010929] RIP: 0010:free_percpu+0x120/0x1f0 [ 50.011980] Code: 43 64 48 01 d0 49 39 c4 0f 83 71 ff ff ff 65 8b 05 85 4f 5c 6f 48 8b 15 ee 4e 20 01 48 98 48 8b 3c c2 4c 01 e7 e8 f0 97 02 00 <48> 8b 58 20 48 8b 53 38 e9 48 ff ff ff f3 c3 48 8b 43 38 48 89 45 [ 50.015205] RSP: 0018:ffffbb8c4057f8e8 EFLAGS: 00010046 [ 50.016501] RAX: 0000000000000000 RBX: ffffa052bff36200 RCX: ffffffff91e0a000 [ 50.018678] RDX: ac20a9ee026510df RSI: 66ec86c56441a2ac RDI: 0000000000000000 [ 50.020214] RBP: ffffbb8c4057f918 R08: ffffffffffffffff R09: 00000000000003b0 [ 50.022224] R10: 0000000000001f80 R11: 00000000ffffffff R12: ac20a9ee026510df [ 50.024191] R13: ac21099b45e510df R14: 0000000000000283 R15: 0000000000000008 [ 50.026148] FS: 00007fde2c539900(0000) GS:ffffa052bc800000(0000) knlGS:0000000000000000 [ 50.028078] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 50.029425] CR2: 0000000000000020 CR3: 00000000360de000 CR4: 00000000003406f0