{
  "cveId": "CVE-2021-47462",
  "url": "https://patchblox.com/security/cve/CVE-2021-47462",
  "summary": "CVE-2021-47462 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-47462, released May 22, 2024. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  mm/mempolicy: do not allow illegal MPOL_F_NUMA_B...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  mm/mempolicy: do not allow illegal MPOL_F_NUMA_BALANCING | MPOL_LOCAL in mbind()  syzbot reported access to unitialized memory in mbind() [1]  Issue came with commit bda420b98505 (\u0022numa balancing: migrate on fault among multiple bound nodes\u0022)  This commit added a new bit in MPOL_MODE_FLAGS, but only checked valid combination (MPOL_F_NUMA_BALANCING can only be used with MPOL_BIND) in do_set_mempolicy()  This patch moves the check in sanitize_mpol_flags() so that it is also used by mbind()    [1]   BUG: KMSAN: uninit-value in __mpol_equal\u002B0x567/0x590 mm/mempolicy.c:2260    __mpol_equal\u002B0x567/0x590 mm/mempolicy.c:2260    mpol_equal include/linux/mempolicy.h:105 [inline]    vma_merge\u002B0x4a1/0x1e60 mm/mmap.c:1190    mbind_range\u002B0xcc8/0x1e80 mm/mempolicy.c:811    do_mbind\u002B0xf42/0x15f0 mm/mempolicy.c:1333    kernel_mbind mm/mempolicy.c:1483 [inline]    __do_sys_mbind mm/mempolicy.c:1490 [inline]    __se_sys_mbind\u002B0x437/0xb80 mm/mempolicy.c:1486    __x64_sys_mbind\u002B0x19d/0x200 mm/mempolicy.c:1486    do_syscall_x64 arch/x86/entry/common.c:51 [inline]    do_syscall_64\u002B0x54/0xd0 arch/x86/entry/common.c:82    entry_SYSCALL_64_after_hwframe\u002B0x44/0xae    Uninit was created at:    slab_alloc_node mm/slub.c:3221 [inline]    slab_alloc mm/slub.c:3230 [inline]    kmem_cache_alloc\u002B0x751/0xff0 mm/slub.c:3235    mpol_new mm/mempolicy.c:293 [inline]    do_mbind\u002B0x912/0x15f0 mm/mempolicy.c:1289    kernel_mbind mm/mempolicy.c:1483 [inline]    __do_sys_mbind mm/mempolicy.c:1490 [inline]    __se_sys_mbind\u002B0x437/0xb80 mm/mempolicy.c:1486    __x64_sys_mbind\u002B0x19d/0x200 mm/mempolicy.c:1486    do_syscall_x64 arch/x86/entry/common.c:51 [inline]    do_syscall_64\u002B0x54/0xd0 arch/x86/entry/common.c:82    entry_SYSCALL_64_after_hwframe\u002B0x44/0xae   =====================================================   Kernel panic - not syncing: panic_on_kmsan set ...   CPU: 0 PID: 15049 Comm: syz-executor.0 Tainted: G    B             5.15.0-rc2-syzkaller #0   Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011   Call Trace:    __dump_stack lib/dump_stack.c:88 [inline]    dump_stack_lvl\u002B0x1ff/0x28e lib/dump_stack.c:106    dump_stack\u002B0x25/0x28 lib/dump_stack.c:113    panic\u002B0x44f/0xdeb kernel/panic.c:232    kmsan_report\u002B0x2ee/0x300 mm/kmsan/report.c:186    __msan_warning\u002B0xd7/0x150 mm/kmsan/instrumentation.c:208    __mpol_equal\u002B0x567/0x590 mm/mempolicy.c:2260    mpol_equal include/linux/mempolicy.h:105 [inline]    vma_merge\u002B0x4a1/0x1e60 mm/mmap.c:1190    mbind_range\u002B0xcc8/0x1e80 mm/mempolicy.c:811    do_mbind\u002B0xf42/0x15f0 mm/mempolicy.c:1333    kernel_mbind mm/mempolicy.c:1483 [inline]    __do_sys_mbind mm/mempolicy.c:1490 [inline]    __se_sys_mbind\u002B0x437/0xb80 mm/mempolicy.c:1486    __x64_sys_mbind\u002B0x19d/0x200 mm/mempolicy.c:1486    do_syscall_x64 arch/x86/entry/common.c:51 [inline]    do_syscall_64\u002B0x54/0xd0 arch/x86/entry/common.c:82    entry_SYSCALL_64_after_hwframe\u002B0x44/0xae",
  "published": "2024-05-22T07:15:11Z",
  "severity": "medium",
  "cvss": 5.5,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.0018,
  "epssPercentile": 0.07634,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "5.14.16-1",
      "fix": "DEBIAN-CVE-2021-47462",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47462",
      "released": "2024-05-22T07:15:11Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "5.14.16-1",
      "fix": "DEBIAN-CVE-2021-47462",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47462",
      "released": "2024-05-22T07:15:11Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "5.14.16-1",
      "fix": "DEBIAN-CVE-2021-47462",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47462",
      "released": "2024-05-22T07:15:11Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T19:12:23Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}