{
  "threat_severity" : "Moderate",
  "public_date" : "2024-05-24T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: ethtool: ioctl: fix potential NULL deref in ethtool_set_coalesce()",
    "id" : "2283393",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2283393"
  },
  "cvss3" : {
    "cvss3_base_score" : "4.7",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-476",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nethtool: ioctl: fix potential NULL deref in ethtool_set_coalesce()\nethtool_set_coalesce() now uses both the .get_coalesce() and\n.set_coalesce() callbacks. But the check for their availability is\nbuggy, so changing the coalesce settings on a device where the driver\nprovides only _one_ of the callbacks results in a NULL pointer\ndereference instead of an -EOPNOTSUPP.\nFix the condition so that the availability of both callbacks is\nensured. This also matches the netlink code.\nNote that reproducing this requires some effort - it only affects the\nlegacy ioctl path, and needs a specific combination of driver options:\n- have .get_coalesce() and .coalesce_supported but no\n.set_coalesce(), or\n- have .set_coalesce() but no .get_coalesce(). Here eg. ethtool doesn't\ncause the crash as it first attempts to call ethtool_get_coalesce()\nand bails out on error.", "A vulnerability was found in the Linux kernel's ethtool implementation in the ioctl handling of coalesce settings, where the system attempts to change coalesce settings using the ethtool_set_coalesce() function without verifying the availability of both the .get_coalesce() and .set_coalesce() callbacks, leading to a potential NULL pointer dereference causing system instability and crashes during network operations." ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2022-05-10T00:00:00Z",
    "advisory" : "RHSA-2022:1975",
    "cpe" : "cpe:/a:redhat:enterprise_linux:8::nfv",
    "package" : "kernel-rt-0:4.18.0-372.9.1.rt7.166.el8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2022-05-10T00:00:00Z",
    "advisory" : "RHSA-2022:1988",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "kernel-0:4.18.0-372.9.1.el8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2022-11-15T00:00:00Z",
    "advisory" : "RHSA-2022:8267",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-162.6.1.el9_1"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2022-11-15T00:00:00Z",
    "advisory" : "RHSA-2022:7933",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9::nfv",
    "package" : "kernel-rt-0:5.14.0-162.6.1.rt21.168.el9_1"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2022-11-15T00:00:00Z",
    "advisory" : "RHSA-2022:8267",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-162.6.1.el9_1"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2021-47556\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-47556\nhttps://lore.kernel.org/linux-cve-announce/2024052443-CVE-2021-47556-558e@gregkh/T" ],
  "name" : "CVE-2021-47556",
  "mitigation" : {
    "value" : "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.",
    "lang" : "en:us"
  },
  "csaw" : false
}