CVE-2024-43824 PCI: endpoint: pci-epf-test: Make use of cached 'epc_features' in pci_epf_test_core_init()

2024-08-1709:21:44

Linux

www.cve.org

cve-2024-43824

pci endpoint

pci-epf-test

epc_features

null check

dereference constraint

smatch warning

linux kernel

EPSS

Percentile

9.5%

JSON

In the Linux kernel, the following vulnerability has been resolved:

PCI: endpoint: pci-epf-test: Make use of cached ‘epc_features’ in pci_epf_test_core_init()

Instead of getting the epc_features from pci_epc_get_features() API, use
the cached pci_epf_test::epc_features value to avoid the NULL check. Since
the NULL check is already performed in pci_epf_test_bind(), having one more
check in pci_epf_test_core_init() is redundant and it is not possible to
hit the NULL pointer dereference.

Also with commit a01e7214bef9 (“PCI: endpoint: Remove “core_init_notifier”
flag”), ‘epc_features’ got dereferenced without the NULL check, leading to
the following false positive Smatch warning:

drivers/pci/endpoint/functions/pci-epf-test.c:784 pci_epf_test_core_init() error: we previously assumed ‘epc_features’ could be null (see line 747)

Thus, remove the redundant NULL check and also use the epc_features::
{msix_capable/msi_capable} flags directly to avoid local variables.

[kwilczynski: commit log]

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/pci/endpoint/functions/pci-epf-test.c"
    ],
    "versions": [
      {
        "version": "5e50ee27d4a5",
        "lessThan": "af4ad016abb1",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "5e50ee27d4a5",
        "lessThan": "5a5095a8bd1b",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/pci/endpoint/functions/pci-epf-test.c"
    ],
    "versions": [
      {
        "version": "5.7",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.7",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.10.3",
        "lessThanOrEqual": "6.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.11",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]