Vulnerability-Lookup

FKIE_CVE-2025-40100

Vulnerability from fkie_nvd - Published: 2025-10-30 10:15 - Updated: 2026-10-19 21:10

Severity

Summary

In the Linux kernel, the following vulnerability has been resolved: btrfs: do not assert we found block group item when creating free space tree Currently, when building a free space tree at populate_free_space_tree(), if we are not using the block group tree feature, we always expect to find block group items (either extent items or a block group item with key type BTRFS_BLOCK_GROUP_ITEM_KEY) when we search the extent tree with btrfs_search_slot_for_read(), so we assert that we found an item. However this expectation is wrong since we can have a new block group created in the current transaction which is still empty and for which we still have not added the block group's item to the extent tree, in which case we do not have any items in the extent tree associated to the block group. The insertion of a new block group's block group item in the extent tree happens at btrfs_create_pending_block_groups() when it calls the helper insert_block_group_item(). This typically is done when a transaction handle is released, committed or when running delayed refs (either as part of a transaction commit or when serving tickets for space reservation if we are low on free space). So remove the assertion at populate_free_space_tree() even when the block group tree feature is not enabled and update the comment to mention this case. Syzbot reported this with the following stack trace: BTRFS info (device loop3 state M): rebuilding free space tree assertion failed: ret == 0 :: 0, in fs/btrfs/free-space-tree.c:1115 ------------[ cut here ]------------ kernel BUG at fs/btrfs/free-space-tree.c:1115! Oops: invalid opcode: 0000 [#1] SMP KASAN PTI CPU: 1 UID: 0 PID: 6352 Comm: syz.3.25 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:populate_free_space_tree+0x700/0x710 fs/btrfs/free-space-tree.c:1115 Code: ff ff e8 d3 (...) RSP: 0018:ffffc9000430f780 EFLAGS: 00010246 RAX: 0000000000000043 RBX: ffff88805b709630 RCX: fea61d0e2e79d000 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: ffffc9000430f8b0 R08: ffffc9000430f4a7 R09: 1ffff92000861e94 R10: dffffc0000000000 R11: fffff52000861e95 R12: 0000000000000001 R13: 1ffff92000861f00 R14: dffffc0000000000 R15: 0000000000000000 FS: 00007f424d9fe6c0(0000) GS:ffff888125afc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd78ad212c0 CR3: 0000000076d68000 CR4: 00000000003526f0 Call Trace: <TASK> btrfs_rebuild_free_space_tree+0x1ba/0x6d0 fs/btrfs/free-space-tree.c:1364 btrfs_start_pre_rw_mount+0x128f/0x1bf0 fs/btrfs/disk-io.c:3062 btrfs_remount_rw fs/btrfs/super.c:1334 [inline] btrfs_reconfigure+0xaed/0x2160 fs/btrfs/super.c:1559 reconfigure_super+0x227/0x890 fs/super.c:1076 do_remount fs/namespace.c:3279 [inline] path_mount+0xd1a/0xfe0 fs/namespace.c:4027 do_mount fs/namespace.c:4048 [inline] __do_sys_mount fs/namespace.c:4236 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4213 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f424e39066a Code: d8 64 89 02 (...) RSP: 002b:00007f424d9fde68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f424d9fdef0 RCX: 00007f424e39066a RDX: 0000200000000180 RSI: 0000200000000380 RDI: 0000000000000000 RBP: 0000200000000180 R08: 00007f424d9fdef0 R09: 0000000000000020 R10: 0000000000000020 R11: 0000000000000246 R12: 0000200000000380 R13: 00007f424d9fdeb0 R14: 0000000000000000 R15: 00002000000002c0 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]---

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/289498da343b05c886f19b4269429606f86dd17b
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/3fdcfd91b93f930d87843156c7c8cc5fbcf9b144
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/4f4b9ca73f84130d9fbb0fc02306ce94ce8bdbe6
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/a5a51bf4e9b7354ce7cd697e610d72c1b33fd949
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/eb145463f22d7d32d426b29fe9810de9e792b6ba

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/btrfs/free-space-tree.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "4f4b9ca73f84130d9fbb0fc02306ce94ce8bdbe6",
              "status": "affected",
              "version": "a5ed91828518ab076209266c2bc510adabd078df",
              "versionType": "git"
            },
            {
              "lessThan": "289498da343b05c886f19b4269429606f86dd17b",
              "status": "affected",
              "version": "a5ed91828518ab076209266c2bc510adabd078df",
              "versionType": "git"
            },
            {
              "lessThan": "3fdcfd91b93f930d87843156c7c8cc5fbcf9b144",
              "status": "affected",
              "version": "a5ed91828518ab076209266c2bc510adabd078df",
              "versionType": "git"
            },
            {
              "lessThan": "eb145463f22d7d32d426b29fe9810de9e792b6ba",
              "status": "affected",
              "version": "a5ed91828518ab076209266c2bc510adabd078df",
              "versionType": "git"
            },
            {
              "lessThan": "a5a51bf4e9b7354ce7cd697e610d72c1b33fd949",
              "status": "affected",
              "version": "a5ed91828518ab076209266c2bc510adabd078df",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/btrfs/free-space-tree.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.5"
            },
            {
              "lessThan": "4.5",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.158",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.114",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.55",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.17.*",
              "status": "unaffected",
              "version": "6.17.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: do not assert we found block group item when creating free space tree\n\nCurrently, when building a free space tree at populate_free_space_tree(),\nif we are not using the block group tree feature, we always expect to find\nblock group items (either extent items or a block group item with key type\nBTRFS_BLOCK_GROUP_ITEM_KEY) when we search the extent tree with\nbtrfs_search_slot_for_read(), so we assert that we found an item. However\nthis expectation is wrong since we can have a new block group created in\nthe current transaction which is still empty and for which we still have\nnot added the block group\u0027s item to the extent tree, in which case we do\nnot have any items in the extent tree associated to the block group.\n\nThe insertion of a new block group\u0027s block group item in the extent tree\nhappens at btrfs_create_pending_block_groups() when it calls the helper\ninsert_block_group_item(). This typically is done when a transaction\nhandle is released, committed or when running delayed refs (either as\npart of a transaction commit or when serving tickets for space reservation\nif we are low on free space).\n\nSo remove the assertion at populate_free_space_tree() even when the block\ngroup tree feature is not enabled and update the comment to mention this\ncase.\n\nSyzbot reported this with the following stack trace:\n\n  BTRFS info (device loop3 state M): rebuilding free space tree\n  assertion failed: ret == 0 :: 0, in fs/btrfs/free-space-tree.c:1115\n  ------------[ cut here ]------------\n  kernel BUG at fs/btrfs/free-space-tree.c:1115!\n  Oops: invalid opcode: 0000 [#1] SMP KASAN PTI\n  CPU: 1 UID: 0 PID: 6352 Comm: syz.3.25 Not tainted syzkaller #0 PREEMPT(full)\n  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025\n  RIP: 0010:populate_free_space_tree+0x700/0x710 fs/btrfs/free-space-tree.c:1115\n  Code: ff ff e8 d3 (...)\n  RSP: 0018:ffffc9000430f780 EFLAGS: 00010246\n  RAX: 0000000000000043 RBX: ffff88805b709630 RCX: fea61d0e2e79d000\n  RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000\n  RBP: ffffc9000430f8b0 R08: ffffc9000430f4a7 R09: 1ffff92000861e94\n  R10: dffffc0000000000 R11: fffff52000861e95 R12: 0000000000000001\n  R13: 1ffff92000861f00 R14: dffffc0000000000 R15: 0000000000000000\n  FS:  00007f424d9fe6c0(0000) GS:ffff888125afc000(0000) knlGS:0000000000000000\n  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n  CR2: 00007fd78ad212c0 CR3: 0000000076d68000 CR4: 00000000003526f0\n  Call Trace:\n   \u003cTASK\u003e\n   btrfs_rebuild_free_space_tree+0x1ba/0x6d0 fs/btrfs/free-space-tree.c:1364\n   btrfs_start_pre_rw_mount+0x128f/0x1bf0 fs/btrfs/disk-io.c:3062\n   btrfs_remount_rw fs/btrfs/super.c:1334 [inline]\n   btrfs_reconfigure+0xaed/0x2160 fs/btrfs/super.c:1559\n   reconfigure_super+0x227/0x890 fs/super.c:1076\n   do_remount fs/namespace.c:3279 [inline]\n   path_mount+0xd1a/0xfe0 fs/namespace.c:4027\n   do_mount fs/namespace.c:4048 [inline]\n   __do_sys_mount fs/namespace.c:4236 [inline]\n   __se_sys_mount+0x313/0x410 fs/namespace.c:4213\n   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n   do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n   RIP: 0033:0x7f424e39066a\n  Code: d8 64 89 02 (...)\n  RSP: 002b:00007f424d9fde68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5\n  RAX: ffffffffffffffda RBX: 00007f424d9fdef0 RCX: 00007f424e39066a\n  RDX: 0000200000000180 RSI: 0000200000000380 RDI: 0000000000000000\n  RBP: 0000200000000180 R08: 00007f424d9fdef0 R09: 0000000000000020\n  R10: 0000000000000020 R11: 0000000000000246 R12: 0000200000000380\n  R13: 00007f424d9fdeb0 R14: 0000000000000000 R15: 00002000000002c0\n   \u003c/TASK\u003e\n  Modules linked in:\n  ---[ end trace 0000000000000000 ]---"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nbtrfs: no afirmar que encontramos un elemento de grupo de bloques al crear el \u00e1rbol de espacio libre\n\nActualmente, al construir un \u00e1rbol de espacio libre en populate_free_space_tree(), si no estamos usando la caracter\u00edstica del \u00e1rbol de grupos de bloques, siempre esperamos encontrar elementos de grupo de bloques (ya sean elementos de extensi\u00f3n o un elemento de grupo de bloques con tipo de clave BTRFS_BLOCK_GROUP_ITEM_KEY) cuando buscamos en el \u00e1rbol de extensiones con btrfs_search_slot_for_read(), por lo que afirmamos que encontramos un elemento. Sin embargo, esta expectativa es incorrecta ya que podemos tener un nuevo grupo de bloques creado en la transacci\u00f3n actual que a\u00fan est\u00e1 vac\u00edo y para el cual a\u00fan no hemos a\u00f1adido el elemento del grupo de bloques al \u00e1rbol de extensiones, en cuyo caso no tenemos ning\u00fan elemento en el \u00e1rbol de extensiones asociado al grupo de bloques.\n\nLa inserci\u00f3n del elemento de grupo de bloques de un nuevo grupo de bloques en el \u00e1rbol de extensiones ocurre en btrfs_create_pending_block_groups() cuando llama a la funci\u00f3n auxiliar insert_block_group_item(). Esto se hace t\u00edpicamente cuando un manejador de transacci\u00f3n es liberado, confirmado o cuando se ejecutan referencias retrasadas (ya sea como parte de una confirmaci\u00f3n de transacci\u00f3n o al atender solicitudes de reserva de espacio si tenemos poco espacio libre).\n\nAs\u00ed que, eliminar la aserci\u00f3n en populate_free_space_tree() incluso cuando la caracter\u00edstica del \u00e1rbol de grupos de bloques no est\u00e1 habilitada y actualizar el comentario para mencionar este caso.\n\nSyzbot inform\u00f3 esto con el siguiente rastreo de pila:\n\n  BTRFS info (device loop3 state M): rebuilding free space tree\n  assertion failed: ret == 0 :: 0, in fs/btrfs/free-space-tree.c:1115\n  ------------[ cut here ]------------\n  kernel BUG at fs/btrfs/free-space-tree.c:1115!\n  Oops: invalid opcode: 0000 [#1] SMP KASAN PTI\n  CPU: 1 UID: 0 PID: 6352 Comm: syz.3.25 Not tainted syzkaller #0 PREEMPT(full)\n  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025\n  RIP: 0010:populate_free_space_tree+0x700/0x710 fs/btrfs/free-space-tree.c:1115\n  Code: ff ff e8 d3 (...)\n  RSP: 0018:ffffc9000430f780 EFLAGS: 00010246\n  RAX: 0000000000000043 RBX: ffff88805b709630 RCX: fea61d0e2e79d000\n  RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000\n  RBP: ffffc9000430f8b0 R08: ffffc9000430f4a7 R09: 1ffff92000861e94\n  R10: dffffc0000000000 R11: fffff52000861e95 R12: 0000000000000001\n  R13: 1ffff92000861f00 R14: dffffc0000000000 R15: 0000000000000000\n  FS:  00007f424d9fe6c0(0000) GS:ffff888125afc000(0000) knlGS:0000000000000000\n  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n  CR2: 00007fd78ad212c0 CR3: 0000000076d68000 CR4: 00000000003526f0\n  Call Trace:\n   \u003cTASK\u003e\n   btrfs_rebuild_free_space_tree+0x1ba/0x6d0 fs/btrfs/free-space-tree.c:1364\n   btrfs_start_pre_rw_mount+0x128f/0x1bf0 fs/btrfs/disk-io.c:3062\n   btrfs_remount_rw fs/btrfs/super.c:1334 [inline]\n   btrfs_reconfigure+0xaed/0x2160 fs/btrfs/super.c:1559\n   reconfigure_super+0x227/0x890 fs/super.c:1076\n   do_remount fs/namespace.c:3279 [inline]\n   path_mount+0xd1a/0xfe0 fs/namespace.c:4027\n   do_mount fs/namespace.c:4048 [inline]\n   __do_sys_mount fs/namespace.c:4236 [inline]\n   __se_sys_mount+0x313/0x410 fs/namespace.c:4213\n   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n   do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n   RIP: 0033:0x7f424e39066a\n  Code: d8 64 89 02 (...)\n  RSP: 002b:00007f424d9fde68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5\n  RAX: ffffffffffffffda RBX: 00007f424d9fdef0 RCX: 00007f424e39066a\n  RDX: 0000200000000180 RSI: 0000200000000380 RDI: 0000000000000000\n  RBP: 0000200000000180 R08: 00007f424d9fdef0 R09: 0000000000000020\n  R10: 0000000000000020 R11: 0000000000000246 R12: 0000200000000380\n  R13: 00007f424d9fdeb0 --TRUNCADO--"
    }
  ],
  "id": "CVE-2025-40100",
  "lastModified": "2026-10-19T21:10:00.160",
  "metrics": {},
  "published": "2025-10-30T10:15:34.423",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/289498da343b05c886f19b4269429606f86dd17b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3fdcfd91b93f930d87843156c7c8cc5fbcf9b144"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4f4b9ca73f84130d9fbb0fc02306ce94ce8bdbe6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a5a51bf4e9b7354ce7cd697e610d72c1b33fd949"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/eb145463f22d7d32d426b29fe9810de9e792b6ba"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Deferred"
}

CVE-2025-40100 (GCVE-0-2025-40100)

Vulnerability from cvelistv5 – Published: 2025-10-30 09:48 – Updated: 2026-05-11 21:42

Title

btrfs: do not assert we found block group item when creating free space tree

Summary

Severity

No CVSS data available.

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 7033 records in the last 180 days details

References

5 references

URL	Tags
https://git.kernel.org/stable/c/4f4b9ca73f84130d9…
https://git.kernel.org/stable/c/289498da343b05c88…
https://git.kernel.org/stable/c/3fdcfd91b93f930d8…
https://git.kernel.org/stable/c/eb145463f22d7d32d…
https://git.kernel.org/stable/c/a5a51bf4e9b7354ce…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: a5ed91828518ab076209266c2bc510adabd078df , < 4f4b9ca73f84130d9fbb0fc02306ce94ce8bdbe6 (git) Affected: a5ed91828518ab076209266c2bc510adabd078df , < 289498da343b05c886f19b4269429606f86dd17b (git) Affected: a5ed91828518ab076209266c2bc510adabd078df , < 3fdcfd91b93f930d87843156c7c8cc5fbcf9b144 (git) Affected: a5ed91828518ab076209266c2bc510adabd078df , < eb145463f22d7d32d426b29fe9810de9e792b6ba (git) Affected: a5ed91828518ab076209266c2bc510adabd078df , < a5a51bf4e9b7354ce7cd697e610d72c1b33fd949 (git)
Linux	Linux	Affected: 4.5 Unaffected: 0 , < 4.5 (semver) Unaffected: 6.1.158 , ≤ 6.1.* (semver) Unaffected: 6.6.114 , ≤ 6.6.* (semver) Unaffected: 6.12.55 , ≤ 6.12.* (semver) Unaffected: 6.17.5 , ≤ 6.17.* (semver) Unaffected: 6.18 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/btrfs/free-space-tree.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "4f4b9ca73f84130d9fbb0fc02306ce94ce8bdbe6",
              "status": "affected",
              "version": "a5ed91828518ab076209266c2bc510adabd078df",
              "versionType": "git"
            },
            {
              "lessThan": "289498da343b05c886f19b4269429606f86dd17b",
              "status": "affected",
              "version": "a5ed91828518ab076209266c2bc510adabd078df",
              "versionType": "git"
            },
            {
              "lessThan": "3fdcfd91b93f930d87843156c7c8cc5fbcf9b144",
              "status": "affected",
              "version": "a5ed91828518ab076209266c2bc510adabd078df",
              "versionType": "git"
            },
            {
              "lessThan": "eb145463f22d7d32d426b29fe9810de9e792b6ba",
              "status": "affected",
              "version": "a5ed91828518ab076209266c2bc510adabd078df",
              "versionType": "git"
            },
            {
              "lessThan": "a5a51bf4e9b7354ce7cd697e610d72c1b33fd949",
              "status": "affected",
              "version": "a5ed91828518ab076209266c2bc510adabd078df",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/btrfs/free-space-tree.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.5"
            },
            {
              "lessThan": "4.5",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.158",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.114",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.55",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.17.*",
              "status": "unaffected",
              "version": "6.17.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.158",
                  "versionStartIncluding": "4.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.114",
                  "versionStartIncluding": "4.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.55",
                  "versionStartIncluding": "4.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.17.5",
                  "versionStartIncluding": "4.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18",
                  "versionStartIncluding": "4.5",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: do not assert we found block group item when creating free space tree\n\nCurrently, when building a free space tree at populate_free_space_tree(),\nif we are not using the block group tree feature, we always expect to find\nblock group items (either extent items or a block group item with key type\nBTRFS_BLOCK_GROUP_ITEM_KEY) when we search the extent tree with\nbtrfs_search_slot_for_read(), so we assert that we found an item. However\nthis expectation is wrong since we can have a new block group created in\nthe current transaction which is still empty and for which we still have\nnot added the block group\u0027s item to the extent tree, in which case we do\nnot have any items in the extent tree associated to the block group.\n\nThe insertion of a new block group\u0027s block group item in the extent tree\nhappens at btrfs_create_pending_block_groups() when it calls the helper\ninsert_block_group_item(). This typically is done when a transaction\nhandle is released, committed or when running delayed refs (either as\npart of a transaction commit or when serving tickets for space reservation\nif we are low on free space).\n\nSo remove the assertion at populate_free_space_tree() even when the block\ngroup tree feature is not enabled and update the comment to mention this\ncase.\n\nSyzbot reported this with the following stack trace:\n\n  BTRFS info (device loop3 state M): rebuilding free space tree\n  assertion failed: ret == 0 :: 0, in fs/btrfs/free-space-tree.c:1115\n  ------------[ cut here ]------------\n  kernel BUG at fs/btrfs/free-space-tree.c:1115!\n  Oops: invalid opcode: 0000 [#1] SMP KASAN PTI\n  CPU: 1 UID: 0 PID: 6352 Comm: syz.3.25 Not tainted syzkaller #0 PREEMPT(full)\n  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025\n  RIP: 0010:populate_free_space_tree+0x700/0x710 fs/btrfs/free-space-tree.c:1115\n  Code: ff ff e8 d3 (...)\n  RSP: 0018:ffffc9000430f780 EFLAGS: 00010246\n  RAX: 0000000000000043 RBX: ffff88805b709630 RCX: fea61d0e2e79d000\n  RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000\n  RBP: ffffc9000430f8b0 R08: ffffc9000430f4a7 R09: 1ffff92000861e94\n  R10: dffffc0000000000 R11: fffff52000861e95 R12: 0000000000000001\n  R13: 1ffff92000861f00 R14: dffffc0000000000 R15: 0000000000000000\n  FS:  00007f424d9fe6c0(0000) GS:ffff888125afc000(0000) knlGS:0000000000000000\n  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n  CR2: 00007fd78ad212c0 CR3: 0000000076d68000 CR4: 00000000003526f0\n  Call Trace:\n   \u003cTASK\u003e\n   btrfs_rebuild_free_space_tree+0x1ba/0x6d0 fs/btrfs/free-space-tree.c:1364\n   btrfs_start_pre_rw_mount+0x128f/0x1bf0 fs/btrfs/disk-io.c:3062\n   btrfs_remount_rw fs/btrfs/super.c:1334 [inline]\n   btrfs_reconfigure+0xaed/0x2160 fs/btrfs/super.c:1559\n   reconfigure_super+0x227/0x890 fs/super.c:1076\n   do_remount fs/namespace.c:3279 [inline]\n   path_mount+0xd1a/0xfe0 fs/namespace.c:4027\n   do_mount fs/namespace.c:4048 [inline]\n   __do_sys_mount fs/namespace.c:4236 [inline]\n   __se_sys_mount+0x313/0x410 fs/namespace.c:4213\n   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n   do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n   RIP: 0033:0x7f424e39066a\n  Code: d8 64 89 02 (...)\n  RSP: 002b:00007f424d9fde68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5\n  RAX: ffffffffffffffda RBX: 00007f424d9fdef0 RCX: 00007f424e39066a\n  RDX: 0000200000000180 RSI: 0000200000000380 RDI: 0000000000000000\n  RBP: 0000200000000180 R08: 00007f424d9fdef0 R09: 0000000000000020\n  R10: 0000000000000020 R11: 0000000000000246 R12: 0000200000000380\n  R13: 00007f424d9fdeb0 R14: 0000000000000000 R15: 00002000000002c0\n   \u003c/TASK\u003e\n  Modules linked in:\n  ---[ end trace 0000000000000000 ]---"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T21:42:30.966Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/4f4b9ca73f84130d9fbb0fc02306ce94ce8bdbe6"
        },
        {
          "url": "https://git.kernel.org/stable/c/289498da343b05c886f19b4269429606f86dd17b"
        },
        {
          "url": "https://git.kernel.org/stable/c/3fdcfd91b93f930d87843156c7c8cc5fbcf9b144"
        },
        {
          "url": "https://git.kernel.org/stable/c/eb145463f22d7d32d426b29fe9810de9e792b6ba"
        },
        {
          "url": "https://git.kernel.org/stable/c/a5a51bf4e9b7354ce7cd697e610d72c1b33fd949"
        }
      ],
      "title": "btrfs: do not assert we found block group item when creating free space tree",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-40100",
    "datePublished": "2025-10-30T09:48:06.521Z",
    "dateReserved": "2025-04-16T07:20:57.164Z",
    "dateUpdated": "2026-05-11T21:42:30.966Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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