CVE-2023-53563
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-10-04

Last updated on: 2026-03-21

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: cpufreq: amd-pstate-ut: Fix kernel panic when loading the driver After loading the amd-pstate-ut driver, amd_pstate_ut_check_perf() and amd_pstate_ut_check_freq() use cpufreq_cpu_get() to get the policy of the CPU and mark it as busy. In these functions, cpufreq_cpu_put() should be used to release the policy, but it is not, so any other entity trying to access the policy is blocked indefinitely. One such scenario is when amd_pstate mode is changed, leading to the following splat: [ 1332.103727] INFO: task bash:2929 blocked for more than 120 seconds. [ 1332.110001] Not tainted 6.5.0-rc2-amd-pstate-ut #5 [ 1332.115315] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1332.123140] task:bash state:D stack:0 pid:2929 ppid:2873 flags:0x00004006 [ 1332.123143] Call Trace: [ 1332.123145] <TASK> [ 1332.123148] __schedule+0x3c1/0x16a0 [ 1332.123154] ? _raw_read_lock_irqsave+0x2d/0x70 [ 1332.123157] schedule+0x6f/0x110 [ 1332.123160] schedule_timeout+0x14f/0x160 [ 1332.123162] ? preempt_count_add+0x86/0xd0 [ 1332.123165] __wait_for_common+0x92/0x190 [ 1332.123168] ? __pfx_schedule_timeout+0x10/0x10 [ 1332.123170] wait_for_completion+0x28/0x30 [ 1332.123173] cpufreq_policy_put_kobj+0x4d/0x90 [ 1332.123177] cpufreq_policy_free+0x157/0x1d0 [ 1332.123178] ? preempt_count_add+0x58/0xd0 [ 1332.123180] cpufreq_remove_dev+0xb6/0x100 [ 1332.123182] subsys_interface_unregister+0x114/0x120 [ 1332.123185] ? preempt_count_add+0x58/0xd0 [ 1332.123187] ? __pfx_amd_pstate_change_driver_mode+0x10/0x10 [ 1332.123190] cpufreq_unregister_driver+0x3b/0xd0 [ 1332.123192] amd_pstate_change_driver_mode+0x1e/0x50 [ 1332.123194] store_status+0xe9/0x180 [ 1332.123197] dev_attr_store+0x1b/0x30 [ 1332.123199] sysfs_kf_write+0x42/0x50 [ 1332.123202] kernfs_fop_write_iter+0x143/0x1d0 [ 1332.123204] vfs_write+0x2df/0x400 [ 1332.123208] ksys_write+0x6b/0xf0 [ 1332.123210] __x64_sys_write+0x1d/0x30 [ 1332.123213] do_syscall_64+0x60/0x90 [ 1332.123216] ? fpregs_assert_state_consistent+0x2e/0x50 [ 1332.123219] ? exit_to_user_mode_prepare+0x49/0x1a0 [ 1332.123223] ? irqentry_exit_to_user_mode+0xd/0x20 [ 1332.123225] ? irqentry_exit+0x3f/0x50 [ 1332.123226] ? exc_page_fault+0x8e/0x190 [ 1332.123228] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 [ 1332.123232] RIP: 0033:0x7fa74c514a37 [ 1332.123234] RSP: 002b:00007ffe31dd0788 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 1332.123238] RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007fa74c514a37 [ 1332.123239] RDX: 0000000000000008 RSI: 000055e27c447aa0 RDI: 0000000000000001 [ 1332.123241] RBP: 000055e27c447aa0 R08: 00007fa74c5d1460 R09: 000000007fffffff [ 1332.123242] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000008 [ 1332.123244] R13: 00007fa74c61a780 R14: 00007fa74c616600 R15: 00007fa74c615a00 [ 1332.123247] </TASK> Fix this by calling cpufreq_cpu_put() wherever necessary. [ rjw: Subject and changelog edits ]
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Meta Information
Published
2025-10-04
Last Modified
2026-03-21
Generated
2026-05-07
AI Q&A
2025-10-04
EPSS Evaluated
2026-05-05
NVD
CVE-2023-53563
EUVD
EUVD-2025-32296
Affected Vendors & Products
Showing 3 associated CPEs
Vendor Product Version / Range
linux linux_kernel From 6.5 (inc) to 6.5.3 (exc)
linux linux_kernel From 6.2 (inc) to 6.4.16 (exc)
linux linux_kernel From 6.1 (inc) to 6.1.53 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability occurs in the Linux kernel's amd-pstate-ut driver where the functions amd_pstate_ut_check_perf() and amd_pstate_ut_check_freq() use cpufreq_cpu_get() to get the CPU policy but fail to release it by not calling cpufreq_cpu_put(). This causes the CPU policy to remain locked, blocking any other process trying to access it indefinitely, which can lead to a kernel panic or system hang.


How can this vulnerability impact me? :

The vulnerability can cause the system to hang or panic when the amd-pstate-ut driver is loaded or when the amd_pstate mode is changed. This happens because the CPU policy remains locked and other processes are blocked indefinitely, potentially leading to system instability and denial of service.


How can this vulnerability be detected on my network or system? Can you suggest some commands?

This vulnerability can be detected by observing kernel panic or hung task messages related to the amd-pstate-ut driver in the system logs. Specifically, look for messages indicating tasks blocked for more than 120 seconds and stack traces involving cpufreq functions. You can check the kernel log using the command: dmesg | grep -i 'amd-pstate-ut' or dmesg | grep -i 'blocked for more than 120 seconds'.


What immediate steps should I take to mitigate this vulnerability?

Immediate mitigation steps include avoiding loading the amd-pstate-ut driver until a patched kernel version is applied. If the driver is already loaded, avoid changing the amd_pstate mode to prevent triggering the kernel panic. Applying the kernel update that includes the fix calling cpufreq_cpu_put() as necessary is the definitive solution.


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