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block: Avoid mounting the bdev pseudo-filesystem in userspace

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: block: Avoid mounting the bdev pseudo-filesystem in userspace The bdev pseudo-filesystem is an internal kernel filesystem with which userspace should not interfere. Unregister it so that userspace cannot even attempt to mount it. This fixes a bug [1] that occurs when attempting to access files, because the system call move_mount() uses pointers declared in the inode_operations structure, which for the bdev pseudo-filesystem are always equal to 0. `inode->i_op = &empty_iops;` [1] BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 23380067 P4D 23380067 PUD 23381067 PMD 0 Oops: 0010 [#1] PREEMPT SMP KASAN NOPTI CPU: 2 PID: 17125 Comm: syz-executor.0 Not tainted 6.1.155-syzkaller-00350-g84221fde2681 #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:0x0 Call Trace: lookup_open.isra.0+0x700/0x1180 fs/namei.c:3460 open_last_lookups fs/namei.c:3550 [inline] path_openat+0x953/0x2700 fs/namei.c:3780 do_filp_open+0x1c5/0x410 fs/namei.c:3810 do_sys_openat2+0x171/0x4d0 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_openat fs/open.c:1350 [inline] __se_sys_openat fs/open.c:1345 [inline] __x64_sys_openat+0x13c/0x1f0 fs/open.c:1345 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0

Announced Source revision 1
Original source ↗

CVE-2026-63810

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-63810

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
        "lessThan": "3d3fcf23993bb756de2f912ab631cfdcc4746554",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
        "lessThan": "99cde0a7b1e98fd3970aabef1300918e91698dd5",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
        "lessThan": "1a02a5028bd6dead1f8503854ef3168d651cd417",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
        "lessThan": "197971e6ffc0a6356b2ba2b22beb42bc0f7e412d",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
        "lessThan": "3804e6de30ae7b053d53341d9d6944356cf23b40",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
        "lessThan": "717f721eb67d2dacd3ed5f7495aef2f442e84ce4",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
        "lessThan": "f73aa66dffcb8e61e78f01b56163ec16a15d06d2",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "block/bdev.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "2.6.12"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "2.6.12",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "5.15.212",
        "versionType": "semver",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.178",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.145",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.95",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.38",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.1.3",
        "versionType": "semver",
        "lessThanOrEqual": "7.1.*"
      },
      {
        "status": "unaffected",
        "version": "7.2",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "block/bdev.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-63810

Source reference: /cveMetadata/cveId

Publisher severity

No explicit severity was provided.

Event
#28462 · Revision 1
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Publisher date
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