FKIE_CVE-2026-63910

Vulnerability from fkie_nvd - Published: 2026-07-19 16:17 - Updated: 2026-07-20 15:16
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: dma-buf: fix UAF in dma_buf_fd() tracepoint Once FD_ADD() returns, the fd is live in the file descriptor table and a thread sharing that table can close() it before DMA_BUF_TRACE() runs. The close drops the last reference, __fput() frees the dma_buf, and the tracepoint then dereferences dmabuf to take dmabuf->name_lock -- slab-use-after-free. Split FD_ADD() back into get_unused_fd_flags() + fd_install() and emit the tracepoint between them. While the fdtable slot is reserved with a NULL file pointer, a racing close() returns -EBADF without entering __fput(), so the dma_buf stays alive across the trace. Same approach as commit 2d76319c4cbb ("dma-buf: fix UAF in dma_buf_put() tracepoint"). This undoes the FD_ADD() conversion done in commit 34dfce523c90 ("dma: convert dma_buf_fd() to FD_ADD()"); FD_ADD() has no place to hook the tracepoint safely.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b569f86e2f8dbf6f11d31d3de794d22e18098b23
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ead6680f354f83966c796fc7f9463a3171789616
Impacted products
Vendor Product Version
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{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/dma-buf/dma-buf.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b569f86e2f8dbf6f11d31d3de794d22e18098b23",
              "status": "affected",
              "version": "281a226314238e8adb08d11b765347687ffb38b9",
              "versionType": "git"
            },
            {
              "lessThan": "ead6680f354f83966c796fc7f9463a3171789616",
              "status": "affected",
              "version": "281a226314238e8adb08d11b765347687ffb38b9",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/dma-buf/dma-buf.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.0"
            },
            {
              "lessThan": "7.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.12",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "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\ndma-buf: fix UAF in dma_buf_fd() tracepoint\n\nOnce FD_ADD() returns, the fd is live in the file descriptor table\nand a thread sharing that table can close() it before DMA_BUF_TRACE()\nruns. The close drops the last reference, __fput() frees the dma_buf,\nand the tracepoint then dereferences dmabuf to take dmabuf-\u003ename_lock\n-- slab-use-after-free.\n\nSplit FD_ADD() back into get_unused_fd_flags() + fd_install() and\nemit the tracepoint between them. While the fdtable slot is reserved\nwith a NULL file pointer, a racing close() returns -EBADF without\nentering __fput(), so the dma_buf stays alive across the trace. Same\napproach as commit 2d76319c4cbb (\"dma-buf: fix UAF in dma_buf_put()\ntracepoint\").\n\nThis undoes the FD_ADD() conversion done in commit 34dfce523c90\n(\"dma: convert dma_buf_fd() to FD_ADD()\"); FD_ADD() has no place to\nhook the tracepoint safely."
    }
  ],
  "id": "CVE-2026-63910",
  "lastModified": "2026-07-20T15:16:55.050",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-19T16:17:08.857",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b569f86e2f8dbf6f11d31d3de794d22e18098b23"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ead6680f354f83966c796fc7f9463a3171789616"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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