Bug 2401530 (CVE-2022-50473)

Summary: CVE-2022-50473 kernel: cpufreq: Init completion before kobject_init_and_add()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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An initialization order bug was found in the Linux kernel's cpufreq subsystem during policy allocation. A local user can trigger this issue when CPU frequency policy initialization fails after kobject registration but before completion initialization, causing the cleanup path to attempt to use an uninitialized completion variable. This results in a page fault and kernel crash, leading to denial of service.
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Description OSIDB Bzimport 2025-10-04 16:05:50 UTC 
In the Linux kernel, the following vulnerability has been resolved:

cpufreq: Init completion before kobject_init_and_add()

In cpufreq_policy_alloc(), it will call uninitialed completion in
cpufreq_sysfs_release() when kobject_init_and_add() fails. And
that will cause a crash such as the following page fault in complete:

BUG: unable to handle page fault for address: fffffffffffffff8
[..]
RIP: 0010:complete+0x98/0x1f0
[..]
Call Trace:
 kobject_put+0x1be/0x4c0
 cpufreq_online.cold+0xee/0x1fd
 cpufreq_add_dev+0x183/0x1e0
 subsys_interface_register+0x3f5/0x4e0
 cpufreq_register_driver+0x3b7/0x670
 acpi_cpufreq_init+0x56c/0x1000 [acpi_cpufreq]
 do_one_initcall+0x13d/0x780
 do_init_module+0x1c3/0x630
 load_module+0x6e67/0x73b0
 __do_sys_finit_module+0x181/0x240
 do_syscall_64+0x35/0x80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
Comment 1 Alexander B 2025-10-06 13:36:01 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025100437-CVE-2022-50473-a1fc@gregkh/T