Bug 2454871 (CVE-2026-31399)

Summary: CVE-2026-31399 kernel: nvdimm/bus: Fix potential use after free in asynchronous initialization
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's nvdimm/bus component. During asynchronous device initialization, if the device_add() function fails in nd_async_device_register(), a use-after-free vulnerability can occur. This happens because the device's reference count drops to zero before the parent pointer is accessed, leading to memory corruption. A local attacker could potentially exploit this to cause system instability or execute arbitrary code.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-04-03 16:05:25 UTC
In the Linux kernel, the following vulnerability has been resolved:

nvdimm/bus: Fix potential use after free in asynchronous initialization

Dingisoul with KASAN reports a use after free if device_add() fails in
nd_async_device_register().

Commit b6eae0f61db2 ("libnvdimm: Hold reference on parent while
scheduling async init") correctly added a reference on the parent device
to be held until asynchronous initialization was complete.  However, if
device_add() results in an allocation failure the ref count of the
device drops to 0 prior to the parent pointer being accessed.  Thus
resulting in use after free.

The bug bot AI correctly identified the fix.  Save a reference to the
parent pointer to be used to drop the parent reference regardless of the
outcome of device_add().