Bug 2348127 (CVE-2022-49549)

Summary: CVE-2022-49549 kernel: x86/MCE/AMD: Fix memory leak when threshold_create_bank() fails
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: low    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-02-26 03:18:33 UTC 
In the Linux kernel, the following vulnerability has been resolved:

x86/MCE/AMD: Fix memory leak when threshold_create_bank() fails

In mce_threshold_create_device(), if threshold_create_bank() fails, the
previously allocated threshold banks array @bp will be leaked because
the call to mce_threshold_remove_device() will not free it.

This happens because mce_threshold_remove_device() fetches the pointer
through the threshold_banks per-CPU variable but bp is written there
only after the bank creation is successful, and not before, when
threshold_create_bank() fails.

Add a helper which unwinds all the bank creation work previously done
and pass into it the previously allocated threshold banks array for
freeing.

  [ bp: Massage. ]
Comment 1 Avinash Hanwate 2025-02-27 07:56:35 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025022615-CVE-2022-49549-db30@gregkh/T