* NULL pointer dereference in cpufreq_update_limits(?) under Xen PV dom0 - regression in 6.13
@ 2025-03-27 0:51 Marek Marczykowski-Górecki
2025-03-27 10:14 ` Jan Beulich
0 siblings, 1 reply; 4+ messages in thread
From: Marek Marczykowski-Górecki @ 2025-03-27 0:51 UTC (permalink / raw)
To: Rafael J. Wysocki, Viresh Kumar
Cc: linux-pm, linux-kernel, linux-acpi, xen-devel, Juergen Gross,
regressions
[-- Attachment #1: Type: text/plain, Size: 5251 bytes --]
Hi,
I've got a report[1] that 6.13.6 crashes as listed below. It worked fine in
6.12.11. We've tried few simple things to narrow the problem down, but
without much success.
This is running in Xen 4.17.5, PV dom0, which probably is relevant here.
This is running on AMD Ryzen 9 7950X3D, with ASRock X670E Taichi
motherboard.
There are few more details in the original report (link below).
The kernel package (including its config saved into /boot) is here:
https://yum.qubes-os.org/r4.2/current/host/fc37/rpm/kernel-latest-6.13.6-1.qubes.fc37.x86_64.rpm
https://yum.qubes-os.org/r4.2/current/host/fc37/rpm/kernel-latest-modules-6.13.6-1.qubes.fc37.x86_64.rpm
The crash message:
[ 9.367048] BUG: kernel NULL pointer dereference, address: 0000000000000070
[ 9.368251] #PF: supervisor read access in kernel mode
[ 9.369273] #PF: error_code(0x0000) - not-present page
[ 9.370346] PGD 0 P4D 0
[ 9.371222] Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
[ 9.372114] CPU: 0 UID: 0 PID: 128 Comm: kworker/0:2 Not tainted 6.13.6-1.qubes.fc37.x86_64 #1
[ 9.373184] Hardware name: ASRock X670E Taichi/X670E Taichi, BIOS 3.20 02/21/2025
[ 9.374183] Workqueue: kacpi_notify acpi_os_execute_deferred
[ 9.375124] RIP: e030:cpufreq_update_limits+0x10/0x30
[ 9.375840] Code: 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 48 8b 05 98 e4 21 02 <48> 8b 40 70 48 85 c0 74 06 e9 a2 36 38 00 cc e9 ec fe ff ff 66 66
[ 9.377009] RSP: e02b:ffffc9004058be28 EFLAGS: 00010246
[ 9.377667] RAX: 0000000000000000 RBX: ffff888005bf4800 RCX: ffff88805d635fa8
[ 9.378415] RDX: ffff888005bf4800 RSI: 0000000000000085 RDI: 0000000000000000
[ 9.379127] RBP: ffff888005cd7800 R08: 0000000000000000 R09: 8080808080808080
[ 9.379887] R10: ffff88800391abc0 R11: fefefefefefefeff R12: ffff888004e8aa00
[ 9.380669] R13: ffff88805d635f80 R14: ffff888004e8aa15 R15: ffff8880059baf00
[ 9.381514] FS: 0000000000000000(0000) GS:ffff88805d600000(0000) knlGS:0000000000000000
[ 9.382345] CS: e030 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9.383045] CR2: 0000000000000070 CR3: 000000000202c000 CR4: 0000000000050660
[ 9.383786] Call Trace:
[ 9.384335] <TASK>
[ 9.384886] ? __die+0x23/0x70
[ 9.385456] ? page_fault_oops+0x95/0x190
[ 9.386036] ? exc_page_fault+0x76/0x190
[ 9.386636] ? asm_exc_page_fault+0x26/0x30
[ 9.387215] ? cpufreq_update_limits+0x10/0x30
[ 9.387805] acpi_processor_notify.part.0+0x79/0x150
[ 9.388402] acpi_ev_notify_dispatch+0x4b/0x80
[ 9.389013] acpi_os_execute_deferred+0x1a/0x30
[ 9.389610] process_one_work+0x186/0x3b0
[ 9.390205] worker_thread+0x251/0x360
[ 9.390765] ? srso_alias_return_thunk+0x5/0xfbef5
[ 9.391376] ? __pfx_worker_thread+0x10/0x10
[ 9.391957] kthread+0xd2/0x100
[ 9.392493] ? __pfx_kthread+0x10/0x10
[ 9.393043] ret_from_fork+0x34/0x50
[ 9.393575] ? __pfx_kthread+0x10/0x10
[ 9.394090] ret_from_fork_asm+0x1a/0x30
[ 9.394621] </TASK>
[ 9.395106] Modules linked in: gpio_generic amd_3d_vcache acpi_pad(-) loop fuse xenfs dm_thin_pool dm_persistent_data dm_bio_prison amdgpu amdxcp i2c_algo_bit drm_ttm_helper ttm crct10dif_pclmul drm_exec crc32_pclmul gpu_sched
crc32c_intel drm_suballoc_helper polyval_clmulni drm_panel_backlight_quirks polyval_generic drm_buddy ghash_clmulni_intel sha512_ssse3 drm_display_helper sha256_ssse3 sha1_ssse3 xhci_pci cec nvme sp5100_tco xhci_hcd nvme_core nvme_auth
video wmi xen_acpi_processor xen_privcmd xen_pciback xen_blkback xen_gntalloc xen_gntdev xen_evtchn scsi_dh_rdac scsi_dh_emc scsi_dh_alua uinput dm_multipath
[ 9.398698] CR2: 0000000000000070
[ 9.399266] ---[ end trace 0000000000000000 ]---
[ 9.399880] RIP: e030:cpufreq_update_limits+0x10/0x30
[ 9.400528] Code: 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 48 8b 05 98 e4 21 02 <48> 8b 40 70 48 85 c0 74 06 e9 a2 36 38 00 cc e9 ec fe ff ff 66 66
[ 9.401673] RSP: e02b:ffffc9004058be28 EFLAGS: 00010246
[ 9.402316] RAX: 0000000000000000 RBX: ffff888005bf4800 RCX: ffff88805d635fa8
[ 9.403060] RDX: ffff888005bf4800 RSI: 0000000000000085 RDI: 0000000000000000
[ 9.403819] RBP: ffff888005cd7800 R08: 0000000000000000 R09: 8080808080808080
[ 9.404581] R10: ffff88800391abc0 R11: fefefefefefefeff R12: ffff888004e8aa00
[ 9.405332] R13: ffff88805d635f80 R14: ffff888004e8aa15 R15: ffff8880059baf00
[ 9.406063] FS: 0000000000000000(0000) GS:ffff88805d600000(0000) knlGS:0000000000000000
[ 9.406830] CS: e030 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9.407561] CR2: 0000000000000070 CR3: 000000000202c000 CR4: 0000000000050660
[ 9.408318] Kernel panic - not syncing: Fatal exception
[ 9.409022] Kernel Offset: disabled
(XEN) Hardware Dom0 crashed: 'noreboot' set - not rebooting.
Looking at the call trace, it's likely related to ACPI, and Xen too, so
I'm adding relevant lists too.
Any ideas?
#regzbot introduced: v6.12.11..v6.13.6
[1] https://forum.qubes-os.org/t/kernel-latest-6-13-6-boot-loop/32926
--
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab
[-- Attachment #2: signature.asc --]
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: NULL pointer dereference in cpufreq_update_limits(?) under Xen PV dom0 - regression in 6.13
2025-03-27 0:51 NULL pointer dereference in cpufreq_update_limits(?) under Xen PV dom0 - regression in 6.13 Marek Marczykowski-Górecki
@ 2025-03-27 10:14 ` Jan Beulich
2025-03-27 11:02 ` Rafael J. Wysocki
0 siblings, 1 reply; 4+ messages in thread
From: Jan Beulich @ 2025-03-27 10:14 UTC (permalink / raw)
To: Marek Marczykowski-Górecki
Cc: linux-pm, linux-kernel, linux-acpi, xen-devel, Juergen Gross,
regressions, Rafael J. Wysocki, Viresh Kumar
On 27.03.2025 01:51, Marek Marczykowski-Górecki wrote:
> Hi,
>
> I've got a report[1] that 6.13.6 crashes as listed below. It worked fine in
> 6.12.11. We've tried few simple things to narrow the problem down, but
> without much success.
>
> This is running in Xen 4.17.5, PV dom0, which probably is relevant here.
> This is running on AMD Ryzen 9 7950X3D, with ASRock X670E Taichi
> motherboard.
> There are few more details in the original report (link below).
>
> The kernel package (including its config saved into /boot) is here:
> https://yum.qubes-os.org/r4.2/current/host/fc37/rpm/kernel-latest-6.13.6-1.qubes.fc37.x86_64.rpm
> https://yum.qubes-os.org/r4.2/current/host/fc37/rpm/kernel-latest-modules-6.13.6-1.qubes.fc37.x86_64.rpm
>
> The crash message:
> [ 9.367048] BUG: kernel NULL pointer dereference, address: 0000000000000070
> [ 9.368251] #PF: supervisor read access in kernel mode
> [ 9.369273] #PF: error_code(0x0000) - not-present page
> [ 9.370346] PGD 0 P4D 0
> [ 9.371222] Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
> [ 9.372114] CPU: 0 UID: 0 PID: 128 Comm: kworker/0:2 Not tainted 6.13.6-1.qubes.fc37.x86_64 #1
> [ 9.373184] Hardware name: ASRock X670E Taichi/X670E Taichi, BIOS 3.20 02/21/2025
> [ 9.374183] Workqueue: kacpi_notify acpi_os_execute_deferred
> [ 9.375124] RIP: e030:cpufreq_update_limits+0x10/0x30
> [ 9.375840] Code: 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 48 8b 05 98 e4 21 02 <48> 8b 40 70 48 85 c0 74 06 e9 a2 36 38 00 cc e9 ec fe ff ff 66 66
> [ 9.377009] RSP: e02b:ffffc9004058be28 EFLAGS: 00010246
> [ 9.377667] RAX: 0000000000000000 RBX: ffff888005bf4800 RCX: ffff88805d635fa8
> [ 9.378415] RDX: ffff888005bf4800 RSI: 0000000000000085 RDI: 0000000000000000
> [ 9.379127] RBP: ffff888005cd7800 R08: 0000000000000000 R09: 8080808080808080
> [ 9.379887] R10: ffff88800391abc0 R11: fefefefefefefeff R12: ffff888004e8aa00
> [ 9.380669] R13: ffff88805d635f80 R14: ffff888004e8aa15 R15: ffff8880059baf00
> [ 9.381514] FS: 0000000000000000(0000) GS:ffff88805d600000(0000) knlGS:0000000000000000
> [ 9.382345] CS: e030 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 9.383045] CR2: 0000000000000070 CR3: 000000000202c000 CR4: 0000000000050660
> [ 9.383786] Call Trace:
> [ 9.384335] <TASK>
> [ 9.384886] ? __die+0x23/0x70
> [ 9.385456] ? page_fault_oops+0x95/0x190
> [ 9.386036] ? exc_page_fault+0x76/0x190
> [ 9.386636] ? asm_exc_page_fault+0x26/0x30
> [ 9.387215] ? cpufreq_update_limits+0x10/0x30
> [ 9.387805] acpi_processor_notify.part.0+0x79/0x150
> [ 9.388402] acpi_ev_notify_dispatch+0x4b/0x80
> [ 9.389013] acpi_os_execute_deferred+0x1a/0x30
> [ 9.389610] process_one_work+0x186/0x3b0
> [ 9.390205] worker_thread+0x251/0x360
> [ 9.390765] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 9.391376] ? __pfx_worker_thread+0x10/0x10
> [ 9.391957] kthread+0xd2/0x100
> [ 9.392493] ? __pfx_kthread+0x10/0x10
> [ 9.393043] ret_from_fork+0x34/0x50
> [ 9.393575] ? __pfx_kthread+0x10/0x10
> [ 9.394090] ret_from_fork_asm+0x1a/0x30
> [ 9.394621] </TASK>
> [ 9.395106] Modules linked in: gpio_generic amd_3d_vcache acpi_pad(-) loop fuse xenfs dm_thin_pool dm_persistent_data dm_bio_prison amdgpu amdxcp i2c_algo_bit drm_ttm_helper ttm crct10dif_pclmul drm_exec crc32_pclmul gpu_sched
> crc32c_intel drm_suballoc_helper polyval_clmulni drm_panel_backlight_quirks polyval_generic drm_buddy ghash_clmulni_intel sha512_ssse3 drm_display_helper sha256_ssse3 sha1_ssse3 xhci_pci cec nvme sp5100_tco xhci_hcd nvme_core nvme_auth
> video wmi xen_acpi_processor xen_privcmd xen_pciback xen_blkback xen_gntalloc xen_gntdev xen_evtchn scsi_dh_rdac scsi_dh_emc scsi_dh_alua uinput dm_multipath
> [ 9.398698] CR2: 0000000000000070
> [ 9.399266] ---[ end trace 0000000000000000 ]---
> [ 9.399880] RIP: e030:cpufreq_update_limits+0x10/0x30
> [ 9.400528] Code: 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 48 8b 05 98 e4 21 02 <48> 8b 40 70 48 85 c0 74 06 e9 a2 36 38 00 cc e9 ec fe ff ff 66 66
> [ 9.401673] RSP: e02b:ffffc9004058be28 EFLAGS: 00010246
> [ 9.402316] RAX: 0000000000000000 RBX: ffff888005bf4800 RCX: ffff88805d635fa8
> [ 9.403060] RDX: ffff888005bf4800 RSI: 0000000000000085 RDI: 0000000000000000
> [ 9.403819] RBP: ffff888005cd7800 R08: 0000000000000000 R09: 8080808080808080
> [ 9.404581] R10: ffff88800391abc0 R11: fefefefefefefeff R12: ffff888004e8aa00
> [ 9.405332] R13: ffff88805d635f80 R14: ffff888004e8aa15 R15: ffff8880059baf00
> [ 9.406063] FS: 0000000000000000(0000) GS:ffff88805d600000(0000) knlGS:0000000000000000
> [ 9.406830] CS: e030 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 9.407561] CR2: 0000000000000070 CR3: 000000000202c000 CR4: 0000000000050660
> [ 9.408318] Kernel panic - not syncing: Fatal exception
> [ 9.409022] Kernel Offset: disabled
> (XEN) Hardware Dom0 crashed: 'noreboot' set - not rebooting.
>
> Looking at the call trace, it's likely related to ACPI, and Xen too, so
> I'm adding relevant lists too.
>
> Any ideas?
>
> #regzbot introduced: v6.12.11..v6.13.6
That code looks to have been introduced for 6.9, so I wonder if so far you merely
were lucky not to have observed any "highest perf changed" notification. See
9c4a13a08a9b ("ACPI: cpufreq: Add highest perf change notification"), which imo
merely adds a 2nd path to a pre-existing problem: cpufreq_update_limits() assumes
that cpufreq_driver is non-NULL, and only checks cpufreq_driver->update_limits.
But of course the assumption there may be legitimate, and it's logic elsewhere
which is or has become flawed.
Jan
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: NULL pointer dereference in cpufreq_update_limits(?) under Xen PV dom0 - regression in 6.13
2025-03-27 10:14 ` Jan Beulich
@ 2025-03-27 11:02 ` Rafael J. Wysocki
2025-03-27 22:02 ` Marek Marczykowski-Górecki
0 siblings, 1 reply; 4+ messages in thread
From: Rafael J. Wysocki @ 2025-03-27 11:02 UTC (permalink / raw)
To: Jan Beulich, Marek Marczykowski-Górecki
Cc: linux-pm, linux-kernel, linux-acpi, xen-devel, Juergen Gross,
regressions, Viresh Kumar
[-- Attachment #1: Type: text/plain, Size: 6233 bytes --]
On Thu, Mar 27, 2025 at 11:14 AM Jan Beulich <jbeulich@suse.com> wrote:
>
> On 27.03.2025 01:51, Marek Marczykowski-Górecki wrote:
> > Hi,
> >
> > I've got a report[1] that 6.13.6 crashes as listed below. It worked fine in
> > 6.12.11. We've tried few simple things to narrow the problem down, but
> > without much success.
> >
> > This is running in Xen 4.17.5, PV dom0, which probably is relevant here.
> > This is running on AMD Ryzen 9 7950X3D, with ASRock X670E Taichi
> > motherboard.
> > There are few more details in the original report (link below).
> >
> > The kernel package (including its config saved into /boot) is here:
> > https://yum.qubes-os.org/r4.2/current/host/fc37/rpm/kernel-latest-6.13.6-1.qubes.fc37.x86_64.rpm
> > https://yum.qubes-os.org/r4.2/current/host/fc37/rpm/kernel-latest-modules-6.13.6-1.qubes.fc37.x86_64.rpm
> >
> > The crash message:
> > [ 9.367048] BUG: kernel NULL pointer dereference, address: 0000000000000070
> > [ 9.368251] #PF: supervisor read access in kernel mode
> > [ 9.369273] #PF: error_code(0x0000) - not-present page
> > [ 9.370346] PGD 0 P4D 0
> > [ 9.371222] Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
> > [ 9.372114] CPU: 0 UID: 0 PID: 128 Comm: kworker/0:2 Not tainted 6.13.6-1.qubes.fc37.x86_64 #1
> > [ 9.373184] Hardware name: ASRock X670E Taichi/X670E Taichi, BIOS 3.20 02/21/2025
> > [ 9.374183] Workqueue: kacpi_notify acpi_os_execute_deferred
> > [ 9.375124] RIP: e030:cpufreq_update_limits+0x10/0x30
> > [ 9.375840] Code: 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 48 8b 05 98 e4 21 02 <48> 8b 40 70 48 85 c0 74 06 e9 a2 36 38 00 cc e9 ec fe ff ff 66 66
> > [ 9.377009] RSP: e02b:ffffc9004058be28 EFLAGS: 00010246
> > [ 9.377667] RAX: 0000000000000000 RBX: ffff888005bf4800 RCX: ffff88805d635fa8
> > [ 9.378415] RDX: ffff888005bf4800 RSI: 0000000000000085 RDI: 0000000000000000
> > [ 9.379127] RBP: ffff888005cd7800 R08: 0000000000000000 R09: 8080808080808080
> > [ 9.379887] R10: ffff88800391abc0 R11: fefefefefefefeff R12: ffff888004e8aa00
> > [ 9.380669] R13: ffff88805d635f80 R14: ffff888004e8aa15 R15: ffff8880059baf00
> > [ 9.381514] FS: 0000000000000000(0000) GS:ffff88805d600000(0000) knlGS:0000000000000000
> > [ 9.382345] CS: e030 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [ 9.383045] CR2: 0000000000000070 CR3: 000000000202c000 CR4: 0000000000050660
> > [ 9.383786] Call Trace:
> > [ 9.384335] <TASK>
> > [ 9.384886] ? __die+0x23/0x70
> > [ 9.385456] ? page_fault_oops+0x95/0x190
> > [ 9.386036] ? exc_page_fault+0x76/0x190
> > [ 9.386636] ? asm_exc_page_fault+0x26/0x30
> > [ 9.387215] ? cpufreq_update_limits+0x10/0x30
> > [ 9.387805] acpi_processor_notify.part.0+0x79/0x150
> > [ 9.388402] acpi_ev_notify_dispatch+0x4b/0x80
> > [ 9.389013] acpi_os_execute_deferred+0x1a/0x30
> > [ 9.389610] process_one_work+0x186/0x3b0
> > [ 9.390205] worker_thread+0x251/0x360
> > [ 9.390765] ? srso_alias_return_thunk+0x5/0xfbef5
> > [ 9.391376] ? __pfx_worker_thread+0x10/0x10
> > [ 9.391957] kthread+0xd2/0x100
> > [ 9.392493] ? __pfx_kthread+0x10/0x10
> > [ 9.393043] ret_from_fork+0x34/0x50
> > [ 9.393575] ? __pfx_kthread+0x10/0x10
> > [ 9.394090] ret_from_fork_asm+0x1a/0x30
> > [ 9.394621] </TASK>
> > [ 9.395106] Modules linked in: gpio_generic amd_3d_vcache acpi_pad(-) loop fuse xenfs dm_thin_pool dm_persistent_data dm_bio_prison amdgpu amdxcp i2c_algo_bit drm_ttm_helper ttm crct10dif_pclmul drm_exec crc32_pclmul gpu_sched
> > crc32c_intel drm_suballoc_helper polyval_clmulni drm_panel_backlight_quirks polyval_generic drm_buddy ghash_clmulni_intel sha512_ssse3 drm_display_helper sha256_ssse3 sha1_ssse3 xhci_pci cec nvme sp5100_tco xhci_hcd nvme_core nvme_auth
> > video wmi xen_acpi_processor xen_privcmd xen_pciback xen_blkback xen_gntalloc xen_gntdev xen_evtchn scsi_dh_rdac scsi_dh_emc scsi_dh_alua uinput dm_multipath
> > [ 9.398698] CR2: 0000000000000070
> > [ 9.399266] ---[ end trace 0000000000000000 ]---
> > [ 9.399880] RIP: e030:cpufreq_update_limits+0x10/0x30
> > [ 9.400528] Code: 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 48 8b 05 98 e4 21 02 <48> 8b 40 70 48 85 c0 74 06 e9 a2 36 38 00 cc e9 ec fe ff ff 66 66
> > [ 9.401673] RSP: e02b:ffffc9004058be28 EFLAGS: 00010246
> > [ 9.402316] RAX: 0000000000000000 RBX: ffff888005bf4800 RCX: ffff88805d635fa8
> > [ 9.403060] RDX: ffff888005bf4800 RSI: 0000000000000085 RDI: 0000000000000000
> > [ 9.403819] RBP: ffff888005cd7800 R08: 0000000000000000 R09: 8080808080808080
> > [ 9.404581] R10: ffff88800391abc0 R11: fefefefefefefeff R12: ffff888004e8aa00
> > [ 9.405332] R13: ffff88805d635f80 R14: ffff888004e8aa15 R15: ffff8880059baf00
> > [ 9.406063] FS: 0000000000000000(0000) GS:ffff88805d600000(0000) knlGS:0000000000000000
> > [ 9.406830] CS: e030 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [ 9.407561] CR2: 0000000000000070 CR3: 000000000202c000 CR4: 0000000000050660
> > [ 9.408318] Kernel panic - not syncing: Fatal exception
> > [ 9.409022] Kernel Offset: disabled
> > (XEN) Hardware Dom0 crashed: 'noreboot' set - not rebooting.
> >
> > Looking at the call trace, it's likely related to ACPI, and Xen too, so
> > I'm adding relevant lists too.
> >
> > Any ideas?
> >
> > #regzbot introduced: v6.12.11..v6.13.6
>
> That code looks to have been introduced for 6.9, so I wonder if so far you merely
> were lucky not to have observed any "highest perf changed" notification. See
> 9c4a13a08a9b ("ACPI: cpufreq: Add highest perf change notification"), which imo
> merely adds a 2nd path to a pre-existing problem: cpufreq_update_limits() assumes
> that cpufreq_driver is non-NULL, and only checks cpufreq_driver->update_limits.
> But of course the assumption there may be legitimate, and it's logic elsewhere
> which is or has become flawed.
cpufreq_update_limits() needs to ensure that the driver is there.
The attached patch should address this issue, Marek please verify.
[-- Attachment #2: cpufreq-update-limits-fix.patch --]
[-- Type: text/x-patch, Size: 510 bytes --]
---
drivers/cpufreq/cpufreq.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -2781,10 +2781,18 @@
*/
void cpufreq_update_limits(unsigned int cpu)
{
+ struct cpufreq_policy *policy;
+
+ policy = cpufreq_cpu_get(cpu);
+ if (!policy)
+ return;
+
if (cpufreq_driver->update_limits)
cpufreq_driver->update_limits(cpu);
else
cpufreq_update_policy(cpu);
+
+ cpufreq_cpu_put(policy);
}
EXPORT_SYMBOL_GPL(cpufreq_update_limits);
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: NULL pointer dereference in cpufreq_update_limits(?) under Xen PV dom0 - regression in 6.13
2025-03-27 11:02 ` Rafael J. Wysocki
@ 2025-03-27 22:02 ` Marek Marczykowski-Górecki
0 siblings, 0 replies; 4+ messages in thread
From: Marek Marczykowski-Górecki @ 2025-03-27 22:02 UTC (permalink / raw)
To: Rafael J. Wysocki
Cc: Jan Beulich, linux-pm, linux-kernel, linux-acpi, xen-devel,
Juergen Gross, regressions, Viresh Kumar
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On Thu, Mar 27, 2025 at 12:02:24PM +0100, Rafael J. Wysocki wrote:
> cpufreq_update_limits() needs to ensure that the driver is there.
>
> The attached patch should address this issue, Marek please verify.
Yes, it fixes the problem, thanks!
--
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab
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2025-03-27 0:51 NULL pointer dereference in cpufreq_update_limits(?) under Xen PV dom0 - regression in 6.13 Marek Marczykowski-Górecki
2025-03-27 10:14 ` Jan Beulich
2025-03-27 11:02 ` Rafael J. Wysocki
2025-03-27 22:02 ` Marek Marczykowski-Górecki
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