Hi Changwei,

Thanks for looking into this. I have run "sudo apport-collect 2170434" as
requested; the logs are now attached to the bug (comments #3-#20), and I've
set the status back to Confirmed.

Note: the logs were collected while booted into 7.0.0-1015-oem with the
workaround "intel_idle.max_cstate=1 processor.max_cstate=1", because the
system oopses or hard-hangs within seconds to minutes without it. So
CurrentDmesg.txt is from a stable boot; the oops excerpt from pstore (no
C-state limit) is in the bug description. I can attach a full
pstore/journal log from a crashing boot if that helps.

I'm happy to test any patched or mainline kernel on this machine (ThinkPad
E14 Gen 7, Core Ultra 7 255H).

Thanks,
Huynh Trong Di

Vào Thứ 6, 16 thg 10, 2026 vào lúc 18:40 Changwei Zou <
[email protected]> đã viết:

> Thank you very much for reporting this issue.
> Could you please provide more information?
> Please boot into the Ubuntu kernel and run the following command in a
> terminal
> to collect debugging information and attach it to this report.
>
> $ sudo apport-collect 2170434
>
> ** Changed in: linux-signed-oem-7.0 (Ubuntu)
>    Importance: Undecided => Medium
>
> ** Changed in: linux-signed-oem-7.0 (Ubuntu)
>        Status: New => Incomplete
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/2170434
>
> Title:
>   Arrow Lake-H (Core Ultra 7 255H): kernel oops / hard hang on exit from
>   core C6 unless intel_idle.max_cstate=1
>
> Status in linux-signed-oem-7.0 package in Ubuntu:
>   Incomplete
>
> Bug description:
>   [Hardware]
>   Lenovo ThinkPad E14 Gen 7 (21SX002SVA), BIOS R30ET59W (1.59) 06/19/2026
>   CPU: Intel Core Ultra 7 255H (family 6, model 197, stepping 2),
> microcode 0x122 (from BIOS)
>   GPU: Arrow Lake-P (i915), Wi-Fi: Arrow Lake CNVi (iwlwifi), NVMe: KIOXIA
> BG6
>   Firmware supports S0 S4 S5 only (s2idle, no S3)
>
>   [Kernel]
>   7.0.0-1015-oem (linux-oem-7.0), Ubuntu 26.04.1 LTS
>
>   [Problem]
>   With default idle settings the system oopses, panics or hard-hangs
> within seconds to minutes
>   (often during boot). Only intel_idle.max_cstate=1 processor.max_cstate=1
> (C1 only) is stable.
>   Windows on the same machine is stable with default power settings.
>
>   intel_idle has no native table for this model and uses ACPI _CST:
>     C1_ACPI = FFH MWAIT 0x0, C2_ACPI = FFH MWAIT 0x21, C3_ACPI = FFH MWAIT
> 0x60
>
>   [Test matrix]
>     intel_idle.max_cstate=1                                   -> stable
>     intel_idle.max_cstate=2 (C1 + MWAIT 0x21)                ->
> oops/double fault within 2-30 s (4/4 boots)
>     no limit + i915.enable_psr=0 enable_panel_replay=0
>       + i915.enable_dc=0 + nvme_core.default_ps_max_latency_us=0 -> oops
> within ~13 s
>     intel_idle.max_cstate=0 (acpi_idle, same _CST states)     -> hard
> hang, no pstore record (4/4 boots)
>   Disabling PSR/Panel Replay/DC, NVMe APST, switching i915 -> xe, BIOS
> update: no effect.
>
>   [Analysis]
>   All oopses are in the idle task (swapper/N) right after wake-up from
> cpuidle_enter_state via an
>   interrupt. Register state looks corrupted after C-state exit: most GPRs
> are zero and a percpu/cpumask
>   pointer read in tick_check_oneshot_broadcast_this_cpu is non-canonical
> (ffff0a80c01fdc98, expected
>   ffff8e84...). The fixup path then faults again -> panic / double fault.
>
>   [Oops excerpt from pstore, max_cstate unlimited]
>   <1>[   13.308089] BUG: unable to handle page fault for address:
> 000000005c415bd8
>   <1>[   13.308109] #PF: supervisor read access in kernel mode
>   <1>[   13.308113] #PF: error_code(0x0000) - not-present page
>   <6>[   13.308116] PGD 0 P4D 0
>   <4>[   13.308122] Oops: Oops: 0000 [#1] SMP NOPTI
>   <4>[   13.308130] CPU: 2 UID: 0 PID: 0 Comm: swapper/2 Tainted: G     U
>             7.0.0-1015-oem #15-Ubuntu PREEMPT(lazy)
>   <4>[   13.308136] Tainted: [U]=USER
>   <4>[   13.308138] Hardware name: LENOVO 21SX002SVA/21SX002SVA, BIOS
> R30ET59W(1.59 ) 06/19/2026
>   <4>[   13.308142] RIP: 0010:search_module_extables+0x45/0x70
>   <4>[   13.308155] Code: ff 48 89 c3 48 85 c0 74 1c 8b b0 2c 01 00 00 85
> f6 74 29 48 8b b8 30 01 00 00 7c 89 e2 e8 37 aa 17 01 d6 89 c3 e8 8b c0 fd
> ff <da> 89 d8 5b 41 5c 5d 31 29 31 f6 31 ff c3 cc cc cc cc e8 74 c0 fd
>   <4>[   13.308158] RSP: 0018:ffffd5a5c0284da8 EFLAGS: 00010046
>   <4>[   13.308162] RAX: 0000000000000000 RBX: 0000000000000000 RCX:
> 0000000000000000
>   <4>[   13.308164] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
> 0000000000000000
>   <4>[   13.308166] RBP: ffffd5a5c0284db8 R08: 0000000000000000 R09:
> 0000000000000000
>   <4>[   13.308168] R10: 0000000000000000 R11: 0000000000000000 R12:
> ffffffff96d8eff3
>   <4>[   13.308170] R13: ffffd5a5c0284f08 R14: 000000000000000d R15:
> 0000000000000000
>   <4>[   13.308173] FS:  0000000000000000(0000) GS:ffff8e84868fb000(0000)
> knlGS:0000000000000000
>   <4>[   13.308176] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>   <4>[   13.308178] CR2: 000000005c415bd8 CR3: 0000000317a44005 CR4:
> 0000000000f72ef0
>   <4>[   13.308181] PKRU: 55555554
>   <4>[   13.308183] Call Trace:
>   <4>[   13.308187]  <IRQ>
>   <4>[   13.308189]  ? tick_check_oneshot_broadcast_this_cpu+0x13/0x60
>   <4>[   13.308206]  search_exception_tables+0x59/0x70
>   <4>[   13.308213]  fixup_exception+0x2c/0x3c0
>   <4>[   13.308220]  gp_try_fixup_and_notify+0x23/0xe0
>   <4>[   13.308228]  exc_general_protection+0xe7/0x410
>   <4>[   13.308235]  ? psi_task_change+0x128/0x1a0
>   <4>[   13.308244]  asm_exc_general_protection+0x27/0x30
>   <4>[   13.308248] RIP:
> 0010:tick_check_oneshot_broadcast_this_cpu+0x13/0x60
>   <4>[   13.308252] Code: 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90
> 90 90 90 90 90 90 90 0f 1f 44 00 00 65 8b 15 48 e0 e8 02 48 8b 05 95 bc 93
> 02 <48> 0f a3 10 73 11 65 48 8b 05 27 e0 e8 02 83 b8 38 70 c2 99 01 74
>   <4>[   13.308254] RSP: 0018:ffffd5a5c0284fb8 EFLAGS: 00010086
>   <4>[   13.308257] RAX: ffff0a80c01fdc98 RBX: ffffd5a5c01abd58 RCX:
> 0000000000000000
>   <4>[   13.308259] RDX: 0000000000000002 RSI: 0000000000000000 RDI:
> 0000000000000000
>   <4>[   13.308261] RBP: ffffd5a5c0284fd0 R08: 0000000000000000 R09:
> 0000000000000000
>   <4>[   13.308263] R10: 0000000000000000 R11: ffffd5a5c0284ff8 R12:
> 0000000000000023
>   <4>[   13.308265] R13: 0000000000000001 R14: 0000000000000000 R15:
> 0000000000000000
>   <4>[   13.308279]  ? tick_irq_enter+0x13/0x90
>   <4>[   13.308285]  irq_enter_rcu+0x75/0x90
>   <4>[   13.308291]  common_interrupt+0xa5/0xe0
>   <4>[   13.308295]  </IRQ>
>   <4>[   13.308296]  <TASK>
>   <4>[   13.308298]  asm_common_interrupt+0x27/0x40
>   <4>[   13.308302] RIP: 0010:cpuidle_enter_state+0xca/0x700
>   <4>[   13.308306] Code: 00 e8 0a c8 dc fe e8 c5 ec ff ff 49 89 c5 0f 1f
> 44 00 00 31 ff e8 e6 b2 da fe 80 7d d0 00 0f 85 c6 01 00 00 fb 0f 1f 44 00
> 00 <45> 85 e4 0f 88 3e 02 00 00 4d 63 fc 49 83 ff 0a 0f 83 1d 05 00 00
>   <4>[   13.308308] RSP: 0018:ffffd5a5c01abe00 EFLAGS: 00000246
>   <4>[   13.308311] RAX: 0000000000000000 RBX: ffff8e84205407c0 RCX:
> 0000000000000000
>   <4>[   13.308313] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
> 0000000000000000
>   <4>[   13.308315] RBP: ffffd5a5c01abe50 R08: 0000000000000000 R09:
> 0000000000000000
>   <4>[   13.308317] R10: 0000000000000000 R11: 0000000000000000 R12:
> 0000000000000003
>   <4>[   13.308319] R13: 000000031938ff16 R14: ffffffff99556100 R15:
> 0000000000000003
>   <4>[   13.308322]  ? tick_nohz_stop_tick+0x5e/0x270
>   <4>[   13.308327]  cpuidle_enter+0x30/0x50
>   <4>[   13.308336]  call_cpuidle+0x21/0x50
>   <4>[   13.308342]  cpuidle_idle_call+0x16b/0x1f0
>   <4>[   13.308347]  do_idle+0x94/0xf0
>   <4>[   13.308351]  cpu_startup_entry+0x29/0x30
>   <4>[   13.308355]  start_secondary+0x125/0x180
>   <4>[   13.308361]  ? soft_restart_cpu+0x14/0x14
>   <4>[   13.308365]  common_startup_64+0x13e/0x141
>
>   ProblemType: Bug
>   DistroRelease: Ubuntu 26.04
>   Package: linux-image-7.0.0-1015-oem 7.0.0-1015.15
>   ProcVersionSignature: Ubuntu 7.0.0-1015.15-oem 7.0.14
>   Uname: Linux 7.0.0-1015-oem x86_64
>   ApportVersion: 2.34.1-0ubuntu0.1
>   Architecture: amd64
>   CasperMD5CheckResult: pass
>   CurrentDesktop: ubuntu:GNOME
>   Date: Sat Oct 10 16:24:21 2026
>   InstallationDate: Installed on 2026-10-05 (5 days ago)
>   InstallationMedia: Ubuntu 24.04.1 LTS "Noble Numbat" - Release amd64
> (20240827.1)
>   ProcEnviron:
>    LANG=en_US.UTF-8
>    PATH=(custom, no user)
>    SHELL=/bin/bash
>    TERM=xterm-256color
>    XDG_RUNTIME_DIR=<set>
>   SourcePackage: linux-signed-oem-7.0
>   UpgradeStatus: Upgraded to resolute on 2026-10-05 (5 days ago)
>
> To manage notifications about this bug go to:
>
> https://bugs.launchpad.net/ubuntu/+source/linux-signed-oem-7.0/+bug/2170434/+subscriptions
>
>

--

*                                                             //Huỳnh Trọng
Dĩ*

-- 
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Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/2170434

Title:
  Arrow Lake-H (Core Ultra 7 255H): kernel oops / hard hang on exit from
  core C6 unless intel_idle.max_cstate=1

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux-signed-oem-7.0/+bug/2170434/+subscriptions


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