{
  "threat_severity" : "Moderate",
  "public_date" : "2026-04-24T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: nilfs2: fix NULL i_assoc_inode dereference in nilfs_mdt_save_to_shadow_map",
    "id" : "2461561",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2461561"
  },
  "cwe" : "CWE-824",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nnilfs2: fix NULL i_assoc_inode dereference in nilfs_mdt_save_to_shadow_map\nThe DAT inode's btree node cache (i_assoc_inode) is initialized lazily\nduring btree operations. However, nilfs_mdt_save_to_shadow_map()\nassumes i_assoc_inode is already initialized when copying dirty pages\nto the shadow map during GC.\nIf NILFS_IOCTL_CLEAN_SEGMENTS is called immediately after mount before\nany btree operation has occurred on the DAT inode, i_assoc_inode is\nNULL leading to a general protection fault.\nFix this by calling nilfs_attach_btree_node_cache() on the DAT inode\nin nilfs_dat_read() at mount time, ensuring i_assoc_inode is always\ninitialized before any GC operation can use it.", "A flaw was found in the `nilfs2` filesystem within the Linux kernel. A local user can trigger a null pointer dereference by calling the `NILFS_IOCTL_CLEAN_SEGMENTS` operation immediately after mounting the filesystem, but before any btree operations have occurred on the Data Allocation Table (DAT) inode. This can lead to a general protection fault, resulting in a system crash and a Denial of Service (DoS)." ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "fix_state" : "Not affected",
    "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" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-31577\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-31577\nhttps://lore.kernel.org/linux-cve-announce/2026042410-CVE-2026-31577-5e81@gregkh/T" ],
  "name" : "CVE-2026-31577",
  "csaw" : false
}