Bug 2440667 (CVE-2025-71233)

Summary: CVE-2025-71233 kernel: Linux kernel: Denial of Service via NULL pointer dereference in PCI endpoint configfs during asynchronous sub-group creation
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: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel. A local user with administrative privileges can trigger a NULL pointer dereference, a type of memory corruption vulnerability, in the PCI endpoint configfs code. This occurs when a user removes a driver directory before an asynchronously created sub-group operation completes. Successful exploitation leads to a kernel crash, resulting in a Denial of Service (DoS).
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Description OSIDB Bzimport 2026-02-18 16:03:34 UTC
In the Linux kernel, the following vulnerability has been resolved:

PCI: endpoint: Avoid creating sub-groups asynchronously

The asynchronous creation of sub-groups by a delayed work could lead to a
NULL pointer dereference when the driver directory is removed before the
work completes.

The crash can be easily reproduced with the following commands:

  # cd /sys/kernel/config/pci_ep/functions/pci_epf_test
  # for i in {1..20}; do mkdir test && rmdir test; done

  BUG: kernel NULL pointer dereference, address: 0000000000000088
  ...
  Call Trace:
   configfs_register_group+0x3d/0x190
   pci_epf_cfs_work+0x41/0x110
   process_one_work+0x18f/0x350
   worker_thread+0x25a/0x3a0

Fix this issue by using configfs_add_default_group() API which does not
have the deadlock problem as configfs_register_group() and does not require
the delayed work handler.

[mani: slightly reworded the description and added stable list]