Bug 2400757 (CVE-2022-50433)

Summary: CVE-2022-50433 kernel: efi: ssdt: Don't free memory if ACPI table was loaded successfully
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedKeywords: Security
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OS: Linux   
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Description OSIDB Bzimport 2025-10-01 12:05:46 UTC
In the Linux kernel, the following vulnerability has been resolved:

efi: ssdt: Don't free memory if ACPI table was loaded successfully

Amadeusz reports KASAN use-after-free errors introduced by commit
3881ee0b1edc ("efi: avoid efivars layer when loading SSDTs from
variables"). The problem appears to be that the memory that holds the
new ACPI table is now freed unconditionally, instead of only when the
ACPI core reported a failure to load the table.

So let's fix this, by omitting the kfree() on success.