{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2025-21954",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2025-21954"
  ],
  "published": "2025-04-01T15:46:27Z",
  "summary": "netmem: prevent TX of unreadable skbs",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetmem: prevent TX of unreadable skbs\n\nCurrently on stable trees we have support for netmem/devmem RX but not\nTX. It is not safe to forward/redirect an RX unreadable netmem packet\ninto the device's TX path, as the device may call dma-mapping APIs on\ndma addrs that should not be passed to it.\n\nFix this by preventing the xmit of unreadable skbs.\n\nTested by configuring tc redirect:\n\nsudo tc qdisc add dev eth1 ingress\nsudo tc filter add dev eth1 ingress protocol ip prio 1 flower ip_proto \\\n\ttcp src_ip 192.168.1.12 action mirred egress redirect dev eth1\n\nBefore, I see unreadable skbs in the driver's TX path passed to dma\nmapping APIs.\n\nAfter, I don't see unreadable skbs in the driver's TX path passed to dma\nmapping APIs.",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:13",
        "name": "linux"
      },
      "versions": [
        "1:6.12.19-1+rpt1~bpo12+1",
        "1:6.12.19-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.12.19+rpt-rpi-2712",
            "binary_version": "1:6.12.19-1+rpt1~bpo12+1"
          },
          {
            "binary_name": "linux-image-6.12.19+rpt-rpi-v6",
            "binary_version": "1:6.12.19-1+rpt1~bpo12+1"
          },
          {
            "binary_name": "linux-image-6.12.19+rpt-rpi-v7",
            "binary_version": "1:6.12.19-1+rpt1~bpo12+1"
          },
          {
            "binary_name": "linux-image-6.12.19+rpt-rpi-v7l",
            "binary_version": "1:6.12.19-1+rpt1~bpo12+1"
          },
          {
            "binary_name": "linux-image-6.12.19+rpt-rpi-v8",
            "binary_version": "1:6.12.19-1+rpt1~bpo12+1"
          },
          {
            "binary_name": "linux-image-6.12.19+rpt-rpi-2712",
            "binary_version": "1:6.12.19-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.12.19+rpt-rpi-v6",
            "binary_version": "1:6.12.19-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.12.19+rpt-rpi-v7",
            "binary_version": "1:6.12.19-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.12.19+rpt-rpi-v7l",
            "binary_version": "1:6.12.19-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.12.19+rpt-rpi-v8",
            "binary_version": "1:6.12.19-1+rpt1"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.12.19-1+rpt1~bpo12+1": {
            "linux_commit": "121c2c384b9c2f4790ffb31b2cd25c7d75c8fda0",
            "upstream_version": "6.12.19",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.12.20"
          },
          "1:6.12.19-1+rpt1": {
            "linux_commit": "121c2c384b9c2f4790ffb31b2cd25c7d75c8fda0",
            "upstream_version": "6.12.19",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.12.20"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-21954"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/454825019d2f0c59e5174ece9e713f45ad80beff"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/1c17c8ced25c5fbe424c7ad7ea11d33014a986b1"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f3600c867c99a2cc8038680ecf211089c50e7971"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T12:19:11Z"
  }
}