Bug 2373687 (CVE-2022-49951)

Summary: CVE-2022-49951 kernel: firmware_loader: Fix use-after-free during unregister
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-06-18 12:13:50 UTC 
In the Linux kernel, the following vulnerability has been resolved:

firmware_loader: Fix use-after-free during unregister

In the following code within firmware_upload_unregister(), the call to
device_unregister() could result in the dev_release function freeing the
fw_upload_priv structure before it is dereferenced for the call to
module_put(). This bug was found by the kernel test robot using
CONFIG_KASAN while running the firmware selftests.

  device_unregister(&fw_sysfs->dev);
  module_put(fw_upload_priv->module);

The problem is fixed by copying fw_upload_priv->module to a local variable
for use when calling device_unregister().
Comment 1 Avinash Hanwate 2025-06-18 17:01:13 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025061810-CVE-2022-49951-bc9b@gregkh/T