{
  "threat_severity" : "Moderate",
  "public_date" : "2026-04-22T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: mm/damon/sysfs: check contexts->nr before accessing contexts_arr[0]",
    "id" : "2460725",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2460725"
  },
  "cvss3" : {
    "cvss3_base_score" : "5.5",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
    "status" : "draft"
  },
  "cwe" : "CWE-1284",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nmm/damon/sysfs: check contexts->nr before accessing contexts_arr[0]\nMultiple sysfs command paths dereference contexts_arr[0] without first\nverifying that kdamond->contexts->nr == 1.  A user can set nr_contexts to\n0 via sysfs while DAMON is running, causing NULL pointer dereferences.\nIn more detail, the issue can be triggered by privileged users like\nbelow.\nFirst, start DAMON and make contexts directory empty\n(kdamond->contexts->nr == 0).\n# damo start\n# cd /sys/kernel/mm/damon/admin/kdamonds/0\n# echo 0 > contexts/nr_contexts\nThen, each of below commands will cause the NULL pointer dereference.\n# echo update_schemes_stats > state\n# echo update_schemes_tried_regions > state\n# echo update_schemes_tried_bytes > state\n# echo update_schemes_effective_quotas > state\n# echo update_tuned_intervals > state\nGuard all commands (except OFF) at the entry point of\ndamon_sysfs_handle_cmd().", "A flaw was found in the Linux kernel. A privileged local user can exploit this by manipulating the `nr_contexts` parameter in the `mm/damon/sysfs` interface to zero while the DAMON (Data Access MONitor) subsystem is active. This leads to a null pointer dereference when certain sysfs commands are subsequently executed, potentially causing a system crash and a Denial of Service (DoS)." ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-31458\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-31458\nhttps://lore.kernel.org/linux-cve-announce/2026042250-CVE-2026-31458-5a8e@gregkh/T" ],
  "name" : "CVE-2026-31458",
  "csaw" : false
}