linux-stable.git/drivers/cpufreq, branch linux-rolling-stable Linux kernel stable tree cpufreq: pcc: fix use-after-free and double free in _OSC evaluation 2026-07-18T14:55:32+00:00 Yuho Choi dbgh9129@gmail.com 2026-04-16T14:46:21+00:00 0e3c739a2f6fc1de5b19a8839ab80696b9cb2a29 commit 266d3dd8b757b48a576e90f018b51f7b7563cc32 upstream. pcc_cpufreq_do_osc() calls acpi_evaluate_object() twice for the two-phase _OSC negotiation. Between the two calls it freed output.pointer but left output.length unchanged. Since acpi_evaluate_object() treats a non-zero length with a non-NULL pointer as an existing buffer to write into, the second call wrote into freed memory (use-after-free). The subsequent kfree(output.pointer) at out_free then freed the same pointer a second time (double free). Reset output.pointer to NULL and output.length to ACPI_ALLOCATE_BUFFER after freeing the first result, so ACPICA allocates a fresh buffer for each phase independently. Fixes: 0f1d683fb35d ("[CPUFREQ] Processor Clocking Control interface driver") Signed-off-by: Yuho Choi <dbgh9129@gmail.com> Reviewed-by: Zhongqiu Han <zhongqiu.han@oss.qualcomm.com> Cc: All applicable <stable@vger.kernel.org> Link: https://patch.msgid.link/20260416144621.93964-1-dbgh9129@gmail.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 266d3dd8b757b48a576e90f018b51f7b7563cc32 upstream.

pcc_cpufreq_do_osc() calls acpi_evaluate_object() twice for the
two-phase _OSC negotiation. Between the two calls it freed
output.pointer but left output.length unchanged. Since
acpi_evaluate_object() treats a non-zero length with a non-NULL
pointer as an existing buffer to write into, the second call wrote
into freed memory (use-after-free). The subsequent kfree(output.pointer)
at out_free then freed the same pointer a second time (double free).

Reset output.pointer to NULL and output.length to ACPI_ALLOCATE_BUFFER
after freeing the first result, so ACPICA allocates a fresh buffer for
each phase independently.

Fixes: 0f1d683fb35d ("[CPUFREQ] Processor Clocking Control interface driver")
Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
Reviewed-by: Zhongqiu Han <zhongqiu.han@oss.qualcomm.com>
Cc: All applicable <stable@vger.kernel.org>
Link: https://patch.msgid.link/20260416144621.93964-1-dbgh9129@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cpufreq: Fix hotplug-suspend race during reboot 2026-07-18T14:55:32+00:00 Tianxiang Chen nanmu@xiaomi.com 2026-04-08T14:19:14+00:00 a0106b41f9a724868d390b8b3b4ea5ca0e04ea53 commit a9029dd55696c651ee46912afa2a166fa456bb3e upstream. During system reboot, cpufreq_suspend() is called via the kernel_restart() -> device_shutdown() path. Unlike the normal system suspend path, the reboot path does not call freeze_processes(), so userspace processes and kernel threads remain active. This allows CPU hotplug operations to run concurrently with cpufreq_suspend(). The original code has no synchronization with CPU hotplug, leading to a race condition where governor_data can be freed by the hotplug path while cpufreq_suspend() is still accessing it, resulting in a null pointer dereference: Unable to handle kernel NULL pointer dereference Call Trace: do_kernel_fault+0x28/0x3c cpufreq_suspend+0xdc/0x160 device_shutdown+0x18/0x200 kernel_restart+0x40/0x80 arm64_sys_reboot+0x1b0/0x200 Fix this by adding cpus_read_lock()/cpus_read_unlock() to cpufreq_suspend() to block CPU hotplug operations while suspend is in progress. Fixes: 65650b35133f ("cpufreq: Avoid cpufreq_suspend() deadlock on system shutdown") Signed-off-by: Tianxiang Chen <nanmu@xiaomi.com> Reviewed-by: Zhongqiu Han <zhongqiu.han@oss.qualcomm.com> Cc: All applicable <stable@vger.kernel.org> [ rjw: Changelog edits ] Link: https://patch.msgid.link/20260408141914.35281-1-nanmu@xiaomi.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a9029dd55696c651ee46912afa2a166fa456bb3e upstream.

During system reboot, cpufreq_suspend() is called via the
kernel_restart() -> device_shutdown() path. Unlike the normal system
suspend path, the reboot path does not call freeze_processes(), so
userspace processes and kernel threads remain active.

This allows CPU hotplug operations to run concurrently with
cpufreq_suspend(). The original code has no synchronization with CPU
hotplug, leading to a race condition where governor_data can be freed
by the hotplug path while cpufreq_suspend() is still accessing it,
resulting in a null pointer dereference:

  Unable to handle kernel NULL pointer dereference
  Call Trace:
   do_kernel_fault+0x28/0x3c
   cpufreq_suspend+0xdc/0x160
   device_shutdown+0x18/0x200
   kernel_restart+0x40/0x80
   arm64_sys_reboot+0x1b0/0x200

Fix this by adding cpus_read_lock()/cpus_read_unlock() to
cpufreq_suspend() to block CPU hotplug operations while suspend is in
progress.

Fixes: 65650b35133f ("cpufreq: Avoid cpufreq_suspend() deadlock on system shutdown")
Signed-off-by: Tianxiang Chen <nanmu@xiaomi.com>
Reviewed-by: Zhongqiu Han <zhongqiu.han@oss.qualcomm.com>
Cc: All applicable <stable@vger.kernel.org>
[ rjw: Changelog edits ]
Link: https://patch.msgid.link/20260408141914.35281-1-nanmu@xiaomi.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cpufreq: intel_pstate: Sync policy->cur during CPU offline 2026-07-18T14:55:32+00:00 Fushuai Wang wangfushuai@baidu.com 2026-05-20T03:21:19+00:00 e0d0adc3d2040dacd7563391ec78d4ac64431ded commit bcbdaa1086c25a8a5d48e04e1b82fdfb0682b681 upstream. When a CPU goes offline with HWP disabled, intel_pstate_set_min_pstate() sets the MSR_IA32_PERF_CTL to minimum frequency to prevent SMT siblings from being restricted. However, the policy->cur value was not updated, leaving it at the previous value. When the CPU comes back online, governor->limits() checks if target_freq equals policy->cur and skips the frequency adjustment if they match. Since policy->cur still holds the previous value, the governor does not call cpufreq_driver->target to update MSR_IA32_PERF_CTL. Fix this by synchronizing policy->cur with the hardware state when setting minimum pstate during CPU offline. Fixes: bb18008f8086 ("intel_pstate: Set core to min P state during core offline") Cc: stable@vger.kernel.org # 3.15+ Suggested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Fushuai Wang <wangfushuai@baidu.com> [ rjw: Subject refinement ] Link: https://patch.msgid.link/20260520032119.30615-1-fushuai.wang@linux.dev Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit bcbdaa1086c25a8a5d48e04e1b82fdfb0682b681 upstream.

When a CPU goes offline with HWP disabled, intel_pstate_set_min_pstate()
sets the MSR_IA32_PERF_CTL to minimum frequency to prevent SMT siblings
from being restricted. However, the policy->cur value was not updated,
leaving it at the previous value.

When the CPU comes back online, governor->limits() checks if target_freq
equals policy->cur and skips the frequency adjustment if they match. Since
policy->cur still holds the previous value, the governor does not call
cpufreq_driver->target to update MSR_IA32_PERF_CTL.

Fix this by synchronizing policy->cur with the hardware state when setting
minimum pstate during CPU offline.

Fixes: bb18008f8086 ("intel_pstate: Set core to min P state during core offline")
Cc: stable@vger.kernel.org # 3.15+
Suggested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>
[ rjw: Subject refinement ]
Link: https://patch.msgid.link/20260520032119.30615-1-fushuai.wang@linux.dev
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cpufreq: qcom-cpufreq-hw: Fix possible double free 2026-07-18T14:55:32+00:00 Guangshuo Li lgs201920130244@gmail.com 2026-05-01T19:00:05+00:00 9de568ef6cdfc7912d5ea8db02843c0e4ef0c75d commit bcb8889c4981fdde42d4fd2c29a77d510fe21da2 upstream. qcom_cpufreq.data is allocated with devm_kzalloc() in probe() as an array of per-domain data. qcom_cpufreq_hw_cpu_init() stores a pointer to one element of this array in policy->driver_data. qcom_cpufreq_hw_cpu_exit() currently calls kfree() on policy->driver_data. This is not valid because the memory is devm-managed. For the first domain, this can free the devm-managed allocation while the devres entry is still active, leading to a possible double free when the platform device is later detached. For other domains, the pointer may refer to an element inside the array rather than the allocation base. Remove the kfree(data) call and let devres release qcom_cpufreq.data. This issue was found by a static analysis tool I am developing. Fixes: 054a3ef683a1 ("cpufreq: qcom-hw: Allocate qcom_cpufreq_data during probe") Cc: stable@vger.kernel.org Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com> Reviewed-by: Zhongqiu Han <zhongqiu.han@oss.qualcomm.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit bcb8889c4981fdde42d4fd2c29a77d510fe21da2 upstream.

qcom_cpufreq.data is allocated with devm_kzalloc() in probe() as an
array of per-domain data. qcom_cpufreq_hw_cpu_init() stores a pointer to
one element of this array in policy->driver_data.

qcom_cpufreq_hw_cpu_exit() currently calls kfree() on policy->driver_data.
This is not valid because the memory is devm-managed. For the first
domain, this can free the devm-managed allocation while the devres entry
is still active, leading to a possible double free when the platform
device is later detached. For other domains, the pointer may refer to an
element inside the array rather than the allocation base.

Remove the kfree(data) call and let devres release qcom_cpufreq.data.

This issue was found by a static analysis tool I am developing.

Fixes: 054a3ef683a1 ("cpufreq: qcom-hw: Allocate qcom_cpufreq_data during probe")
Cc: stable@vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Reviewed-by: Zhongqiu Han <zhongqiu.han@oss.qualcomm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge tag 'amd-pstate-v7.1-2026-06-02' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/superm1/linux 2026-06-08T13:20:04+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2026-06-08T13:20:04+00:00 6100a82e34cb75571feba920a9c18f60698d598a Pull amd-pstate fixes for 7.1 (2026-06-02) from Mario Limonciello: "* Fix a kdoc issue * Fix an issue setting performance state in EPP mode introduced earlier in the cycle from new 7.1 content" * tag 'amd-pstate-v7.1-2026-06-02' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/superm1/linux: cpufreq/amd-pstate: Fix setting EPP in performance mode cpufreq/amd-pstate: drop stale @epp_cached kdoc 
Pull amd-pstate fixes for 7.1 (2026-06-02) from Mario Limonciello:

"* Fix a kdoc issue
 * Fix an issue setting performance state in EPP mode introduced earlier in
   the cycle from new 7.1 content"

* tag 'amd-pstate-v7.1-2026-06-02' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/superm1/linux:
  cpufreq/amd-pstate: Fix setting EPP in performance mode
  cpufreq/amd-pstate: drop stale @epp_cached kdoc
cpufreq/amd-pstate: Fix setting EPP in performance mode 2026-06-02T17:32:06+00:00 Mario Limonciello (AMD) superm1@kernel.org 2026-05-30T15:04:34+00:00 5629eec1a2829871d496f3042884cdc267612f6a EPP 0 is the only supported value in the performance policy. commit 798c47593cca ("cpufreq/amd-pstate: Add support for platform profile class") changed this while adding platform profile support to the dynamic EPP feature, but this actually wasn't necessary since platform profile writes disable manual EPP writes. Restore allowing writing EPP of 0 when in performance mode. Reviewed-by: Marco Scardovi <scardracs@disroot.org> Tested-by: Marco Scardovi <scardracs@disroot.org> Reported-by: Stuart Meckle <stuartmeckle@gmail.com> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221473 Closes: https://gitlab.freedesktop.org/upower/power-profiles-daemon/-/work_items/190 Fixes: 798c47593cca ("cpufreq/amd-pstate: Add support for platform profile class") Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org> 
EPP 0 is the only supported value in the performance policy.
commit 798c47593cca ("cpufreq/amd-pstate: Add support for platform profile
class") changed this while adding platform profile support to the
dynamic EPP feature, but this actually wasn't necessary since platform
profile writes disable manual EPP writes.

Restore allowing writing EPP of 0 when in performance mode.

Reviewed-by: Marco Scardovi <scardracs@disroot.org>
Tested-by: Marco Scardovi <scardracs@disroot.org>
Reported-by: Stuart Meckle <stuartmeckle@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221473
Closes: https://gitlab.freedesktop.org/upower/power-profiles-daemon/-/work_items/190
Fixes: 798c47593cca ("cpufreq/amd-pstate: Add support for platform profile class")
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
cpufreq/amd-pstate: drop stale @epp_cached kdoc 2026-05-26T15:03:15+00:00 Zhan Xusheng zhanxusheng1024@gmail.com 2026-05-26T02:21:31+00:00 3cd07ee35a66038fd1a643632bfc057645e07c9a Commit 4e16c1175238 ("cpufreq/amd-pstate: Stop caching EPP") removed the epp_cached field from struct amd_cpudata in favour of always reading from cppc_req_cached, but the kdoc above the struct still documents @epp_cached. Drop the now-stale @epp_cached entry. Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org> Fixes: 4e16c1175238 ("cpufreq/amd-pstate: Stop caching EPP") Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com> Link: https://lore.kernel.org/r/20260526022131.1302373-1-zhanxusheng@xiaomi.com Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org> 
Commit 4e16c1175238 ("cpufreq/amd-pstate: Stop caching EPP") removed
the epp_cached field from struct amd_cpudata in favour of always
reading from cppc_req_cached, but the kdoc above the struct still
documents @epp_cached.

Drop the now-stale @epp_cached entry.

Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Fixes: 4e16c1175238 ("cpufreq/amd-pstate: Stop caching EPP")
Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com>
Link: https://lore.kernel.org/r/20260526022131.1302373-1-zhanxusheng@xiaomi.com
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
cpufreq/amd-pstate-ut: Disable dynamic_epp after the mode switch 2026-05-26T10:39:28+00:00 K Prateek Nayak kprateek.nayak@amd.com 2026-05-23T05:55:03+00:00 df488cac6140aa04ae52af9b4507d8f99a3762be Dan reported a possible NULL pointer dereference in amd-pstate-ut.c from static analysis and sure enough, running amd-pstate-ut in active mode with amd_dynamic_epp=enable results in a crash as a reult of the policy reference being set to NULL early, before disabling dynamic EPP. Kalpana also reported seeing amd-pstate-ut error out with -EBUSY for "amd_pstate_ut_epp" test when starting from the passive mode and amd_dynamic_epp=enable in the command line. The reason for the failure is that the command line enables dynamic_epp by default after the mode switch and the modifications to EPP values are blocked when running in dynamic EPP mode. Solution to both problems is to toggle off dynamic_epp *after* the mode switch when the driver grabs the policy reference again since the unit test is in full control of the policy after that point. The final restoration step will reset the dynamic_epp state via mode switch based on the initial conditions of the system. Reported-by: Kalpana Shetty <kalpana.shetty@amd.com> Reported-by: Dan Carpenter <error27@gmail.com> Closes: https://lore.kernel.org/linux-pm/ahEq0CvdBX0T7_cO@stanley.mountain/ Fixes: f9f16835d4dc ("cpufreq/amd-pstate-ut: Drop policy reference before driver switch") Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://patch.msgid.link/20260523055503.7651-1-kprateek.nayak@amd.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Dan reported a possible NULL pointer dereference in amd-pstate-ut.c from
static analysis and sure enough, running amd-pstate-ut in active mode
with amd_dynamic_epp=enable results in a crash as a reult of the policy
reference being set to NULL early, before disabling dynamic EPP.

Kalpana also reported seeing amd-pstate-ut error out with -EBUSY for
"amd_pstate_ut_epp" test when starting from the passive mode and
amd_dynamic_epp=enable in the command line. The reason for the failure
is that the command line enables dynamic_epp by default after the mode
switch and the modifications to EPP values are blocked when running in
dynamic EPP mode.

Solution to both problems is to toggle off dynamic_epp *after* the mode
switch when the driver grabs the policy reference again since the unit
test is in full control of the policy after that point.

The final restoration step will reset the dynamic_epp state via mode
switch based on the initial conditions of the system.

Reported-by: Kalpana Shetty <kalpana.shetty@amd.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/linux-pm/ahEq0CvdBX0T7_cO@stanley.mountain/
Fixes: f9f16835d4dc ("cpufreq/amd-pstate-ut: Drop policy reference before driver switch")
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://patch.msgid.link/20260523055503.7651-1-kprateek.nayak@amd.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Merge tag 'amd-pstate-v7.1-2026-05-14' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/superm1/linux into pm-cpufreq-fixes 2026-05-20T20:03:41+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2026-05-20T20:03:41+00:00 a67f3113331d9fb3eb0664602d9b581cb2df7294 Merge amd-pstate fixes for 7.1 (05/14/2026) from Mario Limonciello: "A number of fixes to the dynamic epp feature which was new to kernel 7.1, including making it opt in only." * tag 'amd-pstate-v7.1-2026-05-14' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/superm1/linux: cpufreq/amd-pstate: Drop Kconfig option for dynamic EPP cpufreq/amd-pstate-ut: Drop policy reference before driver switch cpufreq/amd-pstate: Use "epp_default_dc" as default when dynamic_epp is disabled cpufreq/amd-pstate: Reorder notifier unregistration and floor perf reset cpufreq/amd-pstate: Allow writes to dynamic_epp when state isn't modified cpufreq/amd-pstate: Return -ENOMEM on failure to allocate profile_name cpufreq/amd-pstate: Grab "amd_pstate_driver_lock" when toggling dynamic_epp 
Merge amd-pstate fixes for 7.1 (05/14/2026) from Mario Limonciello:

"A number of fixes to the dynamic epp feature which was new
 to kernel 7.1, including making it opt in only."

* tag 'amd-pstate-v7.1-2026-05-14' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/superm1/linux:
  cpufreq/amd-pstate: Drop Kconfig option for dynamic EPP
  cpufreq/amd-pstate-ut: Drop policy reference before driver switch
  cpufreq/amd-pstate: Use "epp_default_dc" as default when dynamic_epp is disabled
  cpufreq/amd-pstate: Reorder notifier unregistration and floor perf reset
  cpufreq/amd-pstate: Allow writes to dynamic_epp when state isn't modified
  cpufreq/amd-pstate: Return -ENOMEM on failure to allocate profile_name
  cpufreq/amd-pstate: Grab "amd_pstate_driver_lock" when toggling dynamic_epp
cpufreq/amd-pstate: Drop Kconfig option for dynamic EPP 2026-05-14T13:47:48+00:00 Mario Limonciello mario.limonciello@amd.com 2026-05-12T22:19:47+00:00 e4e9b7b38d5db2cc6a8770bc0596bb8b36b92b1f There are some performance issues being identified by dynamic EPP and we don't want to have distributions turning it on by default exposing them to users at this time. Drop the kconfig option, and require an explicit opt in from kernel command line or runtime sysfs option to turn it on. Reported-by: Viktor Jägersküpper <viktor_jaegerskuepper@freenet.de> Closes: https://lore.kernel.org/linux-pm/14a87c99-785c-4b16-bfce-35ecbf053448@freenet.de/ Reported-by: Stuart Meckle <stuartmeckle@gmail.com> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221473 Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://lore.kernel.org/r/20260512221947.1652988-1-mario.limonciello@amd.com (fix sysfs file path) Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org> 
There are some performance issues being identified by dynamic EPP
and we don't want to have distributions turning it on by default
exposing them to users at this time.

Drop the kconfig option, and require an explicit opt in from kernel
command line or runtime sysfs option to turn it on.

Reported-by: Viktor Jägersküpper <viktor_jaegerskuepper@freenet.de>
Closes: https://lore.kernel.org/linux-pm/14a87c99-785c-4b16-bfce-35ecbf053448@freenet.de/
Reported-by: Stuart Meckle <stuartmeckle@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221473
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20260512221947.1652988-1-mario.limonciello@amd.com
(fix sysfs file path)
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>