Bug 2461523 (CVE-2026-31594)

Summary: CVE-2026-31594 kernel: PCI: endpoint: pci-epf-vntb: Remove duplicate resource teardown
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's PCI endpoint framework (pci-epf-vntb). This vulnerability arises from a duplicate resource teardown within the `epf_ntb_epc_destroy()` function. A local user could potentially trigger this flaw, leading to a kernel crash and a Denial of Service (DoS) for the affected system.
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Description OSIDB Bzimport 2026-04-24 15:06:28 UTC 
In the Linux kernel, the following vulnerability has been resolved:

PCI: endpoint: pci-epf-vntb: Remove duplicate resource teardown

epf_ntb_epc_destroy() duplicates the teardown that the caller is
supposed to perform later. This leads to an oops when .allow_link fails
or when .drop_link is performed. The following is an example oops of the
former case:

  Unable to handle kernel paging request at virtual address dead000000000108
  [...]
  [dead000000000108] address between user and kernel address ranges
  Internal error: Oops: 0000000096000044 [#1]  SMP
  [...]
  Call trace:
   pci_epc_remove_epf+0x78/0xe0 (P)
   pci_primary_epc_epf_link+0x88/0xa8
   configfs_symlink+0x1f4/0x5a0
   vfs_symlink+0x134/0x1d8
   do_symlinkat+0x88/0x138
   __arm64_sys_symlinkat+0x74/0xe0
  [...]

Remove the helper, and drop pci_epc_put(). EPC device refcounting is
tied to the configfs EPC group lifetime, and pci_epc_put() in the
.drop_link path is sufficient.
Comment 1 Keith Grant 2026-04-24 19:06:10 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026042416-CVE-2026-31594-29aa@gregkh/T