On kernel 5.4.0-40-generic in focal I'm getting errors like this on two machines with different hardware in the first hour after boot:
Jul 04 16:58:32 hostname kernel: BUG: unable to handle page fault for address: ffff9083e222e632 Jul 04 16:58:32 hostname kernel: #PF: supervisor read access in kernel mode Jul 04 16:58:32 hostname kernel: #PF: error_code(0x0000) - not-present page Jul 04 16:58:32 hostname kernel: PGD 3ac205067 P4D 3ac205067 PUD 0 Jul 04 16:58:32 hostname kernel: Oops: 0000 [#1] SMP NOPTI Jul 04 16:58:32 hostname kernel: CPU: 4 PID: 289 Comm: kworker/u16:4 Tainted: G OE 5.4.0-40-generic #44-Ubuntu Jul 04 16:58:32 hostname kernel: Hardware name: LENOVO 20N2CTO1WW/20N2CTO1WW, BIOS N2IET88W (1.66 ) 04/22/2020 Jul 04 16:58:32 hostname kernel: Workqueue: rpciod rpc_async_schedule [sunrpc] Jul 04 16:58:32 hostname kernel: RIP: 0010:kmem_cache_alloc+0x7e/0x230 Jul 04 16:58:32 hostname kernel: Code: 99 01 00 00 4d 8b 07 65 49 8b 50 08 65 4c 03 05 40 9d 56 44 4d 8b 20 4d 85 e4 0f 84 85 01 00 00 41 8b 47 20 49 8b 3f 4c 01 e0 <48> 8b 18 48 89 c1 49 33 9f 70 01 00 00 4c 89 e0 48 0f c9 48 31 cb Jul 04 16:58:32 hostname kernel: RSP: 0018:ffffbc38c046fcc8 EFLAGS: 00010282 Jul 04 16:58:32 hostname kernel: RAX: ffff9083e222e632 RBX: 0000000000000000 RCX: 0000000000000002 Jul 04 16:58:32 hostname kernel: RDX: 0000000000000009 RSI: 0000000000092800 RDI: 0000000000031fb0 Jul 04 16:58:32 hostname kernel: RBP: ffffbc38c046fcf8 R08: ffff90836c331fb0 R09: ffffffffc1436a94 Jul 04 16:58:32 hostname kernel: R10: ffff908368178d2c R11: 0000000000000018 R12: ffff9083e222e632 Jul 04 16:58:32 hostname kernel: R13: 0000000000092800 R14: ffff908367ca6140 R15: ffff908367ca6140 Jul 04 16:58:32 hostname kernel: FS: 0000000000000000(0000) GS:ffff90836c300000(0000) knlGS:0000000000000000 Jul 04 16:58:32 hostname kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Jul 04 16:58:32 hostname kernel: CR2: ffff9083e222e632 CR3: 00000003ab80a003 CR4: 00000000003606e0 Jul 04 16:58:32 hostname kernel: Call Trace: Jul 04 16:58:32 hostname kernel: ? mempool_alloc_slab+0x17/0x20 Jul 04 16:58:32 hostname kernel: mempool_alloc_slab+0x17/0x20 Jul 04 16:58:32 hostname kernel: mempool_alloc+0x64/0x180 Jul 04 16:58:32 hostname kernel: rpc_malloc+0xa1/0xb0 [sunrpc] Jul 04 16:58:32 hostname kernel: call_allocate+0xd1/0x1b0 [sunrpc] Jul 04 16:58:32 hostname kernel: ? call_refreshresult+0x100/0x100 [sunrpc] Jul 04 16:58:32 hostname kernel: __rpc_execute+0x8c/0x3a0 [sunrpc] Jul 04 16:58:32 hostname kernel: rpc_async_schedule+0x30/0x50 [sunrpc] Jul 04 16:58:32 hostname kernel: process_one_work+0x1eb/0x3b0 Jul 04 16:58:32 hostname kernel: worker_thread+0x4d/0x400 Jul 04 16:58:32 hostname kernel: kthread+0x104/0x140 Jul 04 16:58:32 hostname kernel: ? process_one_work+0x3b0/0x3b0 Jul 04 16:58:32 hostname kernel: ? kthread_park+0x90/0x90 Jul 04 16:58:32 hostname kernel: ret_from_fork+0x35/0x40 Jul 04 16:58:32 hostname kernel: Modules linked in: rfcomm rpcsec_gss_krb5 auth_rpcgss nfsv4 nfs lockd grace fscache vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) msr ccm cmac algif_hash algif_skcipher af_alg aufs bnep overlay nls_iso8859_1 mei_hdcp intel_rapl_msr snd_s> Jul 04 16:58:32 hostname kernel: nvram ledtrig_audio mei_me cfg80211 mei processor_thermal_device snd_seq ucsi_acpi typec_ucsi intel_rapl_common intel_soc_dts_iosf snd_seq_device typec intel_pch_thermal snd_timer snd int3403_thermal soundcore int340x_thermal_zone i> Jul 04 16:58:32 hostname kernel: pinctrl_cannonlake video pinctrl_intel Jul 04 16:58:32 hostname kernel: CR2: ffff9083e222e632 Jul 04 16:58:32 hostname kernel: ---[ end trace cbbaed921eb439ce ]--- Jul 04 16:58:32 hostname kernel: RIP: 0010:kmem_cache_alloc+0x7e/0x230 Jul 04 16:58:32 hostname kernel: Code: 99 01 00 00 4d 8b 07 65 49 8b 50 08 65 4c 03 05 40 9d 56 44 4d 8b 20 4d 85 e4 0f 84 85 01 00 00 41 8b 47 20 49 8b 3f 4c 01 e0 <48> 8b 18 48 89 c1 49 33 9f 70 01 00 00 4c 89 e0 48 0f c9 48 31 cb Jul 04 16:58:32 hostname kernel: RSP: 0018:ffffbc38c046fcc8 EFLAGS: 00010282 Jul 04 16:58:32 hostname kernel: RAX: ffff9083e222e632 RBX: 0000000000000000 RCX: 0000000000000002 Jul 04 16:58:32 hostname kernel: RDX: 0000000000000009 RSI: 0000000000092800 RDI: 0000000000031fb0 Jul 04 16:58:32 hostname kernel: RBP: ffffbc38c046fcf8 R08: ffff90836c331fb0 R09: ffffffffc1436a94 Jul 04 16:58:32 hostname kernel: R10: ffff908368178d2c R11: 0000000000000018 R12: ffff9083e222e632 Jul 04 16:58:32 hostname kernel: R13: 0000000000092800 R14: ffff908367ca6140 R15: ffff908367ca6140 Jul 04 16:58:32 hostname kernel: FS: 0000000000000000(0000) GS:ffff90836c300000(0000) knlGS:0000000000000000 Jul 04 16:58:32 hostname kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Jul 04 16:58:32 hostname kernel: CR2: ffff9083e222e632 CR3: 00000003ab80a003 CR4: 00000000003606e0
When booting 5.4.0-39-generic the problem does not occur.
On kernel 5.4.0-40-generic in focal I'm getting errors like this on two machines with different hardware in the first hour after boot:
Jul 04 16:58:32 hostname kernel: BUG: unable to handle page fault for address: ffff9083e222e632 20N2CTO1WW, BIOS N2IET88W (1.66 ) 04/22/2020 cache_alloc+ 0x7e/0x230 46fcc8 EFLAGS: 00010282 0(0000) GS:ffff90836c30 0000(0000) knlGS:000000000 0000000 alloc_slab+ 0x17/0x20 alloc_slab+ 0x17/0x20 alloc+0x64/ 0x180 0xa1/0xb0 [sunrpc] 0xd1/0x1b0 [sunrpc] ult+0x100/ 0x100 [sunrpc] 0x8c/0x3a0 [sunrpc] schedule+ 0x30/0x50 [sunrpc] one_work+ 0x1eb/0x3b0 thread+ 0x4d/0x400 one_work+ 0x3b0/0x3b0 park+0x90/ 0x90 fork+0x35/ 0x40 thermal_ device snd_seq ucsi_acpi typec_ucsi intel_rapl_common intel_soc_dts_iosf snd_seq_device typec intel_pch_thermal snd_timer snd int3403_thermal soundcore int340x_ thermal_ zone i> cache_alloc+ 0x7e/0x230 46fcc8 EFLAGS: 00010282 0(0000) GS:ffff90836c30 0000(0000) knlGS:000000000 0000000
Jul 04 16:58:32 hostname kernel: #PF: supervisor read access in kernel mode
Jul 04 16:58:32 hostname kernel: #PF: error_code(0x0000) - not-present page
Jul 04 16:58:32 hostname kernel: PGD 3ac205067 P4D 3ac205067 PUD 0
Jul 04 16:58:32 hostname kernel: Oops: 0000 [#1] SMP NOPTI
Jul 04 16:58:32 hostname kernel: CPU: 4 PID: 289 Comm: kworker/u16:4 Tainted: G OE 5.4.0-40-generic #44-Ubuntu
Jul 04 16:58:32 hostname kernel: Hardware name: LENOVO 20N2CTO1WW/
Jul 04 16:58:32 hostname kernel: Workqueue: rpciod rpc_async_schedule [sunrpc]
Jul 04 16:58:32 hostname kernel: RIP: 0010:kmem_
Jul 04 16:58:32 hostname kernel: Code: 99 01 00 00 4d 8b 07 65 49 8b 50 08 65 4c 03 05 40 9d 56 44 4d 8b 20 4d 85 e4 0f 84 85 01 00 00 41 8b 47 20 49 8b 3f 4c 01 e0 <48> 8b 18 48 89 c1 49 33 9f 70 01 00 00 4c 89 e0 48 0f c9 48 31 cb
Jul 04 16:58:32 hostname kernel: RSP: 0018:ffffbc38c0
Jul 04 16:58:32 hostname kernel: RAX: ffff9083e222e632 RBX: 0000000000000000 RCX: 0000000000000002
Jul 04 16:58:32 hostname kernel: RDX: 0000000000000009 RSI: 0000000000092800 RDI: 0000000000031fb0
Jul 04 16:58:32 hostname kernel: RBP: ffffbc38c046fcf8 R08: ffff90836c331fb0 R09: ffffffffc1436a94
Jul 04 16:58:32 hostname kernel: R10: ffff908368178d2c R11: 0000000000000018 R12: ffff9083e222e632
Jul 04 16:58:32 hostname kernel: R13: 0000000000092800 R14: ffff908367ca6140 R15: ffff908367ca6140
Jul 04 16:58:32 hostname kernel: FS: 000000000000000
Jul 04 16:58:32 hostname kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Jul 04 16:58:32 hostname kernel: CR2: ffff9083e222e632 CR3: 00000003ab80a003 CR4: 00000000003606e0
Jul 04 16:58:32 hostname kernel: Call Trace:
Jul 04 16:58:32 hostname kernel: ? mempool_
Jul 04 16:58:32 hostname kernel: mempool_
Jul 04 16:58:32 hostname kernel: mempool_
Jul 04 16:58:32 hostname kernel: rpc_malloc+
Jul 04 16:58:32 hostname kernel: call_allocate+
Jul 04 16:58:32 hostname kernel: ? call_refreshres
Jul 04 16:58:32 hostname kernel: __rpc_execute+
Jul 04 16:58:32 hostname kernel: rpc_async_
Jul 04 16:58:32 hostname kernel: process_
Jul 04 16:58:32 hostname kernel: worker_
Jul 04 16:58:32 hostname kernel: kthread+0x104/0x140
Jul 04 16:58:32 hostname kernel: ? process_
Jul 04 16:58:32 hostname kernel: ? kthread_
Jul 04 16:58:32 hostname kernel: ret_from_
Jul 04 16:58:32 hostname kernel: Modules linked in: rfcomm rpcsec_gss_krb5 auth_rpcgss nfsv4 nfs lockd grace fscache vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) msr ccm cmac algif_hash algif_skcipher af_alg aufs bnep overlay nls_iso8859_1 mei_hdcp intel_rapl_msr snd_s>
Jul 04 16:58:32 hostname kernel: nvram ledtrig_audio mei_me cfg80211 mei processor_
Jul 04 16:58:32 hostname kernel: pinctrl_cannonlake video pinctrl_intel
Jul 04 16:58:32 hostname kernel: CR2: ffff9083e222e632
Jul 04 16:58:32 hostname kernel: ---[ end trace cbbaed921eb439ce ]---
Jul 04 16:58:32 hostname kernel: RIP: 0010:kmem_
Jul 04 16:58:32 hostname kernel: Code: 99 01 00 00 4d 8b 07 65 49 8b 50 08 65 4c 03 05 40 9d 56 44 4d 8b 20 4d 85 e4 0f 84 85 01 00 00 41 8b 47 20 49 8b 3f 4c 01 e0 <48> 8b 18 48 89 c1 49 33 9f 70 01 00 00 4c 89 e0 48 0f c9 48 31 cb
Jul 04 16:58:32 hostname kernel: RSP: 0018:ffffbc38c0
Jul 04 16:58:32 hostname kernel: RAX: ffff9083e222e632 RBX: 0000000000000000 RCX: 0000000000000002
Jul 04 16:58:32 hostname kernel: RDX: 0000000000000009 RSI: 0000000000092800 RDI: 0000000000031fb0
Jul 04 16:58:32 hostname kernel: RBP: ffffbc38c046fcf8 R08: ffff90836c331fb0 R09: ffffffffc1436a94
Jul 04 16:58:32 hostname kernel: R10: ffff908368178d2c R11: 0000000000000018 R12: ffff9083e222e632
Jul 04 16:58:32 hostname kernel: R13: 0000000000092800 R14: ffff908367ca6140 R15: ffff908367ca6140
Jul 04 16:58:32 hostname kernel: FS: 000000000000000
Jul 04 16:58:32 hostname kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Jul 04 16:58:32 hostname kernel: CR2: ffff9083e222e632 CR3: 00000003ab80a003 CR4: 00000000003606e0
When booting 5.4.0-39-generic the problem does not occur.