Public bug reported:
[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)
** Affects: linux-signed-oem-7.0 (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug resolute wayland-session
--
You received this bug notification because you are a member of Ubuntu
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
--
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
