FKIE_CVE-2026-74734

Vulnerability from fkie_nvd - Published: 2026-08-26 15:16 - Updated: 2026-08-26 15:16
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: firewire: ohci: fix NULL pointer dereference in ar_context_release During the error handling path of the driver's probe function, a NULL pointer dereference can occur in ar_context_release(). When pci_probe() fails early (e.g., if pcim_enable_device() or MMIO mapping fails), the devres cleanup mechanism invokes release_ohci(). This function unconditionally calls ar_context_release() to clean up the asynchronous receive contexts. However, if ar_context_init() was not yet called, ctx->ohci remains NULL (as the fw_ohci structure is zero-initialized by devres_alloc()). ar_context_release() immediately dereferences ctx->ohci to get the dev pointer before checking if the context was actually initialized, leading to a crash: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] RIP: 0010:ar_context_release+0x3f/0x380 drivers/firewire/ohci.c:543 Call Trace: release_ohci+0x3f/0x60 drivers/firewire/ohci.c:3567 release_nodes drivers/base/devres.c:546 [inline] devres_release_all+0x1a8/0x260 drivers/base/devres.c:576 device_unbind_cleanup drivers/base/dd.c:597 [inline] really_probe+0x451/0xae0 drivers/base/dd.c:772 To fix this, move the assignment of the dev pointer after the !ctx->buffer check. If ctx->buffer is NULL, it indicates that the context was never successfully initialized and there is nothing to release, safely avoiding the dereference of the uninitialized ctx->ohci pointer.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/42d217add8d80d6e7d9f58f80d11ea9b07ea113e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7d228ba43279de2d191f25e139fad166409c2c06
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ed5470771c7ed7f959230c4697f316af83426a90
Impacted products
Vendor Product Version
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{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/firewire/ohci.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ed5470771c7ed7f959230c4697f316af83426a90",
              "status": "affected",
              "version": "5716e58aecdd4f7225c2e46ce903a839fc54f22f",
              "versionType": "git"
            },
            {
              "lessThan": "7d228ba43279de2d191f25e139fad166409c2c06",
              "status": "affected",
              "version": "5716e58aecdd4f7225c2e46ce903a839fc54f22f",
              "versionType": "git"
            },
            {
              "lessThan": "42d217add8d80d6e7d9f58f80d11ea9b07ea113e",
              "status": "affected",
              "version": "5716e58aecdd4f7225c2e46ce903a839fc54f22f",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/firewire/ohci.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.5"
            },
            {
              "lessThan": "6.5",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.46",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfirewire: ohci: fix NULL pointer dereference in ar_context_release\n\nDuring the error handling path of the driver\u0027s probe function, a NULL\npointer dereference can occur in ar_context_release().\n\nWhen pci_probe() fails early (e.g., if pcim_enable_device() or MMIO mapping\nfails), the devres cleanup mechanism invokes release_ohci(). This function\nunconditionally calls ar_context_release() to clean up the asynchronous\nreceive contexts. However, if ar_context_init() was not yet called,\nctx-\u003eohci remains NULL (as the fw_ohci structure is zero-initialized by\ndevres_alloc()).\n\nar_context_release() immediately dereferences ctx-\u003eohci to get the dev\npointer before checking if the context was actually initialized, leading to\na crash:\n\nOops: general protection fault, probably for non-canonical address\n0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI\nKASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]\nRIP: 0010:ar_context_release+0x3f/0x380 drivers/firewire/ohci.c:543\nCall Trace:\n release_ohci+0x3f/0x60 drivers/firewire/ohci.c:3567\n release_nodes drivers/base/devres.c:546 [inline]\n devres_release_all+0x1a8/0x260 drivers/base/devres.c:576\n device_unbind_cleanup drivers/base/dd.c:597 [inline]\n really_probe+0x451/0xae0 drivers/base/dd.c:772\n\nTo fix this, move the assignment of the dev pointer after the !ctx-\u003ebuffer\ncheck. If ctx-\u003ebuffer is NULL, it indicates that the context was never\nsuccessfully initialized and there is nothing to release, safely avoiding\nthe dereference of the uninitialized ctx-\u003eohci pointer."
    }
  ],
  "id": "CVE-2026-74734",
  "lastModified": "2026-08-26T15:16:51.927",
  "metrics": {},
  "published": "2026-08-26T15:16:51.927",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/42d217add8d80d6e7d9f58f80d11ea9b07ea113e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7d228ba43279de2d191f25e139fad166409c2c06"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ed5470771c7ed7f959230c4697f316af83426a90"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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