{
  "threat_severity" : "Moderate",
  "public_date" : "2024-05-21T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: mm/slub: actually fix freelist pointer vs redzoning",
    "id" : "2282597",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2282597"
  },
  "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" : "verified"
  },
  "cwe" : "CWE-99",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nmm/slub: actually fix freelist pointer vs redzoning\nIt turns out that SLUB redzoning (\"slub_debug=Z\") checks from\ns->object_size rather than from s->inuse (which is normally bumped to\nmake room for the freelist pointer), so a cache created with an object\nsize less than 24 would have the freelist pointer written beyond\ns->object_size, causing the redzone to be corrupted by the freelist\npointer.  This was very visible with \"slub_debug=ZF\":\nBUG test (Tainted: G    B            ): Right Redzone overwritten\n-----------------------------------------------------------------------------\nINFO: 0xffff957ead1c05de-0xffff957ead1c05df @offset=1502. First byte 0x1a instead of 0xbb\nINFO: Slab 0xffffef3950b47000 objects=170 used=170 fp=0x0000000000000000 flags=0x8000000000000200\nINFO: Object 0xffff957ead1c05d8 @offset=1496 fp=0xffff957ead1c0620\nRedzone  (____ptrval____): bb bb bb bb bb bb bb bb               ........\nObject   (____ptrval____): 00 00 00 00 00 f6 f4 a5               ........\nRedzone  (____ptrval____): 40 1d e8 1a aa                        @....\nPadding  (____ptrval____): 00 00 00 00 00 00 00 00               ........\nAdjust the offset to stay within s->object_size.\n(Note that no caches of in this size range are known to exist in the\nkernel currently.)" ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2023-05-16T00:00:00Z",
    "advisory" : "RHSA-2023:2951",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "kernel-0:4.18.0-477.10.1.el8_8"
  } ],
  "package_state" : [ {
    "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" : "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"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "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-2021-47221\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-47221\nhttps://lore.kernel.org/linux-cve-announce/2024052135-CVE-2021-47221-4e17@gregkh/T" ],
  "name" : "CVE-2021-47221",
  "csaw" : false
}