CVE-2025-21658

{"id": "CVE-2025-21658", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "[email protected]", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}, {"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}]}, "published": "2025-01-21T13:15:09.437", "references": [{"url": "https://git.kernel.org/stable/c/24b85a8b0310e0144da9ab30be42e87e6476638a", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/6aecd91a5c5b68939cf4169e32bc49f3cd2dd329", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/aee5f69f3e6cd82bfefaca1b70b40b6cd8f3f784", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "[email protected]", "description": [{"lang": "en", "value": "CWE-476"}]}, {"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "description": [{"lang": "en", "value": "CWE-476"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: avoid NULL pointer dereference if no valid extent tree\n\n[BUG]\nSyzbot reported a crash with the following call trace:\n\n BTRFS info (device loop0): scrub: started on devid 1\n BUG: kernel NULL pointer dereference, address: 0000000000000208\n #PF: supervisor read access in kernel mode\n #PF: error_code(0x0000) - not-present page\n PGD 106e70067 P4D 106e70067 PUD 107143067 PMD 0\n Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI\n CPU: 1 UID: 0 PID: 689 Comm: repro Kdump: loaded Tainted: G O 6.13.0-rc4-custom+ #206\n Tainted: [O]=OOT_MODULE\n Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022\n RIP: 0010:find_first_extent_item+0x26/0x1f0 [btrfs]\n Call Trace:\n <TASK>\n scrub_find_fill_first_stripe+0x13d/0x3b0 [btrfs]\n scrub_simple_mirror+0x175/0x260 [btrfs]\n scrub_stripe+0x5d4/0x6c0 [btrfs]\n scrub_chunk+0xbb/0x170 [btrfs]\n scrub_enumerate_chunks+0x2f4/0x5f0 [btrfs]\n btrfs_scrub_dev+0x240/0x600 [btrfs]\n btrfs_ioctl+0x1dc8/0x2fa0 [btrfs]\n ? do_sys_openat2+0xa5/0xf0\n __x64_sys_ioctl+0x97/0xc0\n do_syscall_64+0x4f/0x120\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n </TASK>\n\n[CAUSE]\nThe reproducer is using a corrupted image where extent tree root is\ncorrupted, thus forcing to use \"rescue=all,ro\" mount option to mount the\nimage.\n\nThen it triggered a scrub, but since scrub relies on extent tree to find\nwhere the data/metadata extents are, scrub_find_fill_first_stripe()\nrelies on an non-empty extent root.\n\nBut unfortunately scrub_find_fill_first_stripe() doesn't really expect\nan NULL pointer for extent root, it use extent_root to grab fs_info and\ntriggered a NULL pointer dereference.\n\n[FIX]\nAdd an extra check for a valid extent root at the beginning of\nscrub_find_fill_first_stripe().\n\nThe new error path is introduced by 42437a6386ff (\"btrfs: introduce\nmount option rescue=ignorebadroots\"), but that's pretty old, and later\ncommit b979547513ff (\"btrfs: scrub: introduce helper to find and fill\nsector info for a scrub_stripe\") changed how we do scrub.\n\nSo for kernels older than 6.6, the fix will need manual backport."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: btrfs: evitar la desreferencia de puntero NULL si no hay un \u00e1rbol de extensi\u00f3n v\u00e1lido [ERROR] Syzbot inform\u00f3 de un fallo con el siguiente seguimiento de llamada: Informaci\u00f3n de BTRFS (bucle de dispositivo 0): scrub: iniciado en devid 1 ERROR: desreferencia de puntero NULL del kernel, direcci\u00f3n: 0000000000000208 #PF: acceso de lectura de supervisor en modo kernel #PF: error_code(0x0000) - p\u00e1gina no presente PGD 106e70067 P4D 106e70067 PUD 107143067 PMD 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 1 UID: 0 PID: 689 Comm: repro Kdump: cargado Tainted: G O 6.13.0-rc4-custom+ #206 Tainted: [O]=OOT_MODULE Nombre de hardware: PC est\u00e1ndar QEMU (Q35 + ICH9, 2009), BIOS desconocido 02/02/2022 RIP: 0010:find_first_extent_item+0x26/0x1f0 [btrfs] Seguimiento de llamadas: Scrub_find_fill_first_stripe+0x13d/0x3b0 [btrfs] Scrub_simple_mirror+0x175/0x260 [btrfs] Scrub_stripe+0x5d4/0x6c0 [btrfs] Scrub_chunk+0xbb/0x170 [btrfs] Scrub_enumerate_chunks+0x2f4/0x5f0 [btrfs] btrfs_scrub_dev+0x240/0x600 [btrfs] btrfs_ioctl+0x1dc8/0x2fa0 [btrfs] ? do_sys_openat2+0xa5/0xf0 __x64_sys_ioctl+0x97/0xc0 do_syscall_64+0x4f/0x120 entry_SYSCALL_64_after_hwframe+0x76/0x7e [CAUSA] El reproductor est\u00e1 usando una imagen da\u00f1ada donde la ra\u00edz del \u00e1rbol de extensi\u00f3n est\u00e1 da\u00f1ada, lo que obliga a usar la opci\u00f3n de montaje \"rescue=all,ro\" para montar la imagen. Luego, activ\u00f3 una limpieza, pero como la limpieza depende del \u00e1rbol de extensi\u00f3n para encontrar d\u00f3nde est\u00e1n las extensiones de datos/metadatos, scrub_find_fill_first_stripe() depende de una ra\u00edz de extensi\u00f3n no vac\u00eda. Pero desafortunadamente scrub_find_fill_first_stripe() no espera realmente un puntero NULL para la ra\u00edz de la extensi\u00f3n, usa extended_root para obtener fs_info y activa una desreferencia de puntero NULL. [SOLUCI\u00d3N] Agregue una verificaci\u00f3n adicional para una ra\u00edz de extensi\u00f3n v\u00e1lida al comienzo de scrub_find_fill_first_stripe(). La nueva ruta de error es introducida por 42437a6386ff (\"btrfs: introduce mount option rescue=ignorebadroots\"), pero eso es bastante antiguo, y el commit posterior b979547513ff (\"btrfs: scrub: introduce helper to find and fill sector info for a scrub_stripe\") cambi\u00f3 la forma en que realizamos el scrub. Entonces, para los kernels anteriores a 6.6, la soluci\u00f3n necesitar\u00e1 una adaptaci\u00f3n manual. "}], "lastModified": "2025-10-01T20:18:17.093", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "AD41C3D4-D314-4BC5-888E-E1B87323349D", "versionEndExcluding": "6.6.72", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "02D604F6-10D1-4F7B-A022-0888406A1121", "versionEndExcluding": "6.12.10", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "62567B3C-6CEE-46D0-BC2E-B3717FBF7D13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "5A073481-106D-4B15-B4C7-FB0213B8E1D4"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.13:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "DE491969-75AE-4A6B-9A58-8FC5AF98798F"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.13:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "93C0660D-7FB8-4FBA-892A-B064BA71E49E"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.13:rc5:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "034C36A6-C481-41F3-AE9A-D116E5BE6895"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.13:rc6:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8AF9DC49-2085-4FFB-A7E3-73DFAFECC7F2"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}