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CVE-2025-40235 (GCVE-0-2025-40235)

Vulnerability from cvelistv5 – Published: 2025-12-04 15:31 – Updated: 2026-05-11 21:45
VLAI
Title
btrfs: directly free partially initialized fs_info in btrfs_check_leaked_roots()
Summary
In the Linux kernel, the following vulnerability has been resolved: btrfs: directly free partially initialized fs_info in btrfs_check_leaked_roots() If fs_info->super_copy or fs_info->super_for_commit allocated failed in btrfs_get_tree_subvol(), then no need to call btrfs_free_fs_info(). Otherwise btrfs_check_leaked_roots() would access NULL pointer because fs_info->allocated_roots had not been initialised. syzkaller reported the following information: ------------[ cut here ]------------ BUG: unable to handle page fault for address: fffffffffffffbb0 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 64c9067 P4D 64c9067 PUD 64cb067 PMD 0 Oops: Oops: 0000 [#1] SMP KASAN PTI CPU: 0 UID: 0 PID: 1402 Comm: syz.1.35 Not tainted 6.15.8 #4 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), (...) RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline] RIP: 0010:refcount_read include/linux/refcount.h:170 [inline] RIP: 0010:btrfs_check_leaked_roots+0x18f/0x2c0 fs/btrfs/disk-io.c:1230 [...] Call Trace: <TASK> btrfs_free_fs_info+0x310/0x410 fs/btrfs/disk-io.c:1280 btrfs_get_tree_subvol+0x592/0x6b0 fs/btrfs/super.c:2029 btrfs_get_tree+0x63/0x80 fs/btrfs/super.c:2097 vfs_get_tree+0x98/0x320 fs/super.c:1759 do_new_mount+0x357/0x660 fs/namespace.c:3899 path_mount+0x716/0x19c0 fs/namespace.c:4226 do_mount fs/namespace.c:4239 [inline] __do_sys_mount fs/namespace.c:4450 [inline] __se_sys_mount fs/namespace.c:4427 [inline] __x64_sys_mount+0x28c/0x310 fs/namespace.c:4427 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x92/0x180 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f032eaffa8d [...]
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 3bb17a25bcb09abbd667c6ac86c7c9109ae82bcd , < b1c2b4e6ffd307720ab6ce42f6749b0c02ba0a73 (git)
Affected: 3bb17a25bcb09abbd667c6ac86c7c9109ae82bcd , < 0c2b2d4d053e9840e6da6ed581befa20309f281a (git)
Affected: 3bb17a25bcb09abbd667c6ac86c7c9109ae82bcd , < 17679ac6df6c4830ba711835aa8cf961be36cfa1 (git)
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Linux Linux Affected: 6.8
Unaffected: 0 , < 6.8 (semver)
Unaffected: 6.12.56 , ≤ 6.12.* (semver)
Unaffected: 6.17.6 , ≤ 6.17.* (semver)
Unaffected: 6.18 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/btrfs/super.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "lessThan": "b1c2b4e6ffd307720ab6ce42f6749b0c02ba0a73",
              "status": "affected",
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              "versionType": "git"
            },
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              "lessThan": "0c2b2d4d053e9840e6da6ed581befa20309f281a",
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              "version": "3bb17a25bcb09abbd667c6ac86c7c9109ae82bcd",
              "versionType": "git"
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              "versionType": "git"
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          "programFiles": [
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.8"
            },
            {
              "lessThan": "6.8",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.56",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.17.*",
              "status": "unaffected",
              "version": "6.17.6",
              "versionType": "semver"
            },
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              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.56",
                  "versionStartIncluding": "6.8",
                  "vulnerable": true
                },
                {
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                  "versionStartIncluding": "6.8",
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                  "versionEndExcluding": "6.18",
                  "versionStartIncluding": "6.8",
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              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: directly free partially initialized fs_info in btrfs_check_leaked_roots()\n\nIf fs_info-\u003esuper_copy or fs_info-\u003esuper_for_commit allocated failed in\nbtrfs_get_tree_subvol(), then no need to call btrfs_free_fs_info().\nOtherwise btrfs_check_leaked_roots() would access NULL pointer because\nfs_info-\u003eallocated_roots had not been initialised.\n\nsyzkaller reported the following information:\n  ------------[ cut here ]------------\n  BUG: unable to handle page fault for address: fffffffffffffbb0\n  #PF: supervisor read access in kernel mode\n  #PF: error_code(0x0000) - not-present page\n  PGD 64c9067 P4D 64c9067 PUD 64cb067 PMD 0\n  Oops: Oops: 0000 [#1] SMP KASAN PTI\n  CPU: 0 UID: 0 PID: 1402 Comm: syz.1.35 Not tainted 6.15.8 #4 PREEMPT(lazy)\n  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), (...)\n  RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]\n  RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]\n  RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline]\n  RIP: 0010:refcount_read include/linux/refcount.h:170 [inline]\n  RIP: 0010:btrfs_check_leaked_roots+0x18f/0x2c0 fs/btrfs/disk-io.c:1230\n  [...]\n  Call Trace:\n   \u003cTASK\u003e\n   btrfs_free_fs_info+0x310/0x410 fs/btrfs/disk-io.c:1280\n   btrfs_get_tree_subvol+0x592/0x6b0 fs/btrfs/super.c:2029\n   btrfs_get_tree+0x63/0x80 fs/btrfs/super.c:2097\n   vfs_get_tree+0x98/0x320 fs/super.c:1759\n   do_new_mount+0x357/0x660 fs/namespace.c:3899\n   path_mount+0x716/0x19c0 fs/namespace.c:4226\n   do_mount fs/namespace.c:4239 [inline]\n   __do_sys_mount fs/namespace.c:4450 [inline]\n   __se_sys_mount fs/namespace.c:4427 [inline]\n   __x64_sys_mount+0x28c/0x310 fs/namespace.c:4427\n   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n   do_syscall_64+0x92/0x180 arch/x86/entry/syscall_64.c:94\n   entry_SYSCALL_64_after_hwframe+0x76/0x7e\n  RIP: 0033:0x7f032eaffa8d\n  [...]"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T21:45:24.427Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/b1c2b4e6ffd307720ab6ce42f6749b0c02ba0a73"
        },
        {
          "url": "https://git.kernel.org/stable/c/0c2b2d4d053e9840e6da6ed581befa20309f281a"
        },
        {
          "url": "https://git.kernel.org/stable/c/17679ac6df6c4830ba711835aa8cf961be36cfa1"
        }
      ],
      "title": "btrfs: directly free partially initialized fs_info in btrfs_check_leaked_roots()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-40235",
    "datePublished": "2025-12-04T15:31:25.785Z",
    "dateReserved": "2025-04-16T07:20:57.180Z",
    "dateUpdated": "2026-05-11T21:45:24.427Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2025-40235",
      "date": "2026-09-16",
      "epss": "0.00199",
      "percentile": "0.09917"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2025-40235\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-12-04T16:16:16.407\",\"lastModified\":\"2026-06-17T09:21:30.233\",\"vulnStatus\":\"Deferred\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nbtrfs: directly free partially initialized fs_info in btrfs_check_leaked_roots()\\n\\nIf fs_info-\u003esuper_copy or fs_info-\u003esuper_for_commit allocated failed in\\nbtrfs_get_tree_subvol(), then no need to call btrfs_free_fs_info().\\nOtherwise btrfs_check_leaked_roots() would access NULL pointer because\\nfs_info-\u003eallocated_roots had not been initialised.\\n\\nsyzkaller reported the following information:\\n  ------------[ cut here ]------------\\n  BUG: unable to handle page fault for address: fffffffffffffbb0\\n  #PF: supervisor read access in kernel mode\\n  #PF: error_code(0x0000) - not-present page\\n  PGD 64c9067 P4D 64c9067 PUD 64cb067 PMD 0\\n  Oops: Oops: 0000 [#1] SMP KASAN PTI\\n  CPU: 0 UID: 0 PID: 1402 Comm: syz.1.35 Not tainted 6.15.8 #4 PREEMPT(lazy)\\n  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), (...)\\n  RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]\\n  RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]\\n  RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline]\\n  RIP: 0010:refcount_read include/linux/refcount.h:170 [inline]\\n  RIP: 0010:btrfs_check_leaked_roots+0x18f/0x2c0 fs/btrfs/disk-io.c:1230\\n  [...]\\n  Call Trace:\\n   \u003cTASK\u003e\\n   btrfs_free_fs_info+0x310/0x410 fs/btrfs/disk-io.c:1280\\n   btrfs_get_tree_subvol+0x592/0x6b0 fs/btrfs/super.c:2029\\n   btrfs_get_tree+0x63/0x80 fs/btrfs/super.c:2097\\n   vfs_get_tree+0x98/0x320 fs/super.c:1759\\n   do_new_mount+0x357/0x660 fs/namespace.c:3899\\n   path_mount+0x716/0x19c0 fs/namespace.c:4226\\n   do_mount fs/namespace.c:4239 [inline]\\n   __do_sys_mount fs/namespace.c:4450 [inline]\\n   __se_sys_mount fs/namespace.c:4427 [inline]\\n   __x64_sys_mount+0x28c/0x310 fs/namespace.c:4427\\n   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\\n   do_syscall_64+0x92/0x180 arch/x86/entry/syscall_64.c:94\\n   entry_SYSCALL_64_after_hwframe+0x76/0x7e\\n  RIP: 0033:0x7f032eaffa8d\\n  [...]\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"fs/btrfs/super.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"3bb17a25bcb09abbd667c6ac86c7c9109ae82bcd\",\"lessThan\":\"b1c2b4e6ffd307720ab6ce42f6749b0c02ba0a73\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"3bb17a25bcb09abbd667c6ac86c7c9109ae82bcd\",\"lessThan\":\"0c2b2d4d053e9840e6da6ed581befa20309f281a\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"3bb17a25bcb09abbd667c6ac86c7c9109ae82bcd\",\"lessThan\":\"17679ac6df6c4830ba711835aa8cf961be36cfa1\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"fs/btrfs/super.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.8\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.8\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.56\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.17.6\",\"lessThanOrEqual\":\"6.17.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/0c2b2d4d053e9840e6da6ed581befa20309f281a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/17679ac6df6c4830ba711835aa8cf961be36cfa1\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/b1c2b4e6ffd307720ab6ce42f6749b0c02ba0a73\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Low",
      "current_release_date": "2026-06-30T10:16:01+00:00",
      "cve": "CVE-2025-40235",
      "id": "CVE-2025-40235",
      "initial_release_date": "2025-12-04T00:00:00+00:00",
      "product_status:known_affected": "14",
      "product_status:known_not_affected": "260",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: btrfs: directly free partially initialized fs_info in btrfs_check_leaked_roots()",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-40235.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-11T01:54:39Z",
      "cve": "CVE-2025-40235",
      "id": "CVE-2025-40235",
      "initial_release_date": "2025-12-05T00:25:50Z",
      "product_status:first_fixed": "2",
      "product_status:known_affected": "394",
      "product_status:known_not_affected": "512",
      "product_status:recommended": "172",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2025-40235",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2025-40235.json",
      "version": "22"
    }
  }
}



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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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