{
  "threat_severity" : "Moderate",
  "public_date" : "2024-10-21T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: mm, slub: avoid zeroing kmalloc redzone",
    "id" : "2320484",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2320484"
  },
  "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"
  },
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nmm, slub: avoid zeroing kmalloc redzone\nSince commit 946fa0dbf2d8 (\"mm/slub: extend redzone check to extra\nallocated kmalloc space than requested\"), setting orig_size treats\nthe wasted space (object_size - orig_size) as a redzone. However with\ninit_on_free=1 we clear the full object->size, including the redzone.\nAdditionally we clear the object metadata, including the stored orig_size,\nmaking it zero, which makes check_object() treat the whole object as a\nredzone.\nThese issues lead to the following BUG report with \"slub_debug=FUZ\ninit_on_free=1\":\n[    0.000000] =============================================================================\n[    0.000000] BUG kmalloc-8 (Not tainted): kmalloc Redzone overwritten\n[    0.000000] -----------------------------------------------------------------------------\n[    0.000000]\n[    0.000000] 0xffff000010032858-0xffff00001003285f @offset=2136. First byte 0x0 instead of 0xcc\n[    0.000000] FIX kmalloc-8: Restoring kmalloc Redzone 0xffff000010032858-0xffff00001003285f=0xcc\n[    0.000000] Slab 0xfffffdffc0400c80 objects=36 used=23 fp=0xffff000010032a18 flags=0x3fffe0000000200(workingset|node=0|zone=0|lastcpupid=0x1ffff)\n[    0.000000] Object 0xffff000010032858 @offset=2136 fp=0xffff0000100328c8\n[    0.000000]\n[    0.000000] Redzone  ffff000010032850: cc cc cc cc cc cc cc cc                          ........\n[    0.000000] Object   ffff000010032858: cc cc cc cc cc cc cc cc                          ........\n[    0.000000] Redzone  ffff000010032860: cc cc cc cc cc cc cc cc                          ........\n[    0.000000] Padding  ffff0000100328b4: 00 00 00 00 00 00 00 00 00 00 00 00              ............\n[    0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.11.0-rc3-next-20240814-00004-g61844c55c3f4 #144\n[    0.000000] Hardware name: NXP i.MX95 19X19 board (DT)\n[    0.000000] Call trace:\n[    0.000000]  dump_backtrace+0x90/0xe8\n[    0.000000]  show_stack+0x18/0x24\n[    0.000000]  dump_stack_lvl+0x74/0x8c\n[    0.000000]  dump_stack+0x18/0x24\n[    0.000000]  print_trailer+0x150/0x218\n[    0.000000]  check_object+0xe4/0x454\n[    0.000000]  free_to_partial_list+0x2f8/0x5ec\nTo address the issue, use orig_size to clear the used area. And restore\nthe value of orig_size after clear the remaining area.\nWhen CONFIG_SLUB_DEBUG not defined, (get_orig_size()' directly returns\ns->object_size. So when using memset to init the area, the size can simply\nbe orig_size, as orig_size returns object_size when CONFIG_SLUB_DEBUG not\nenabled. And orig_size can never be bigger than object_size." ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-05-13T00:00:00Z",
    "advisory" : "RHSA-2025:6966",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-570.12.1.el9_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-05-13T00:00:00Z",
    "advisory" : "RHSA-2025:6966",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-570.12.1.el9_6"
  } ],
  "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" : "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" : "Will not fix",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2024-49885\nhttps://nvd.nist.gov/vuln/detail/CVE-2024-49885\nhttps://lore.kernel.org/linux-cve-announce/2024102117-CVE-2024-49885-d5d0@gregkh/T" ],
  "name" : "CVE-2024-49885",
  "csaw" : false
}