CVE-2025-37999

{"id": "CVE-2025-37999", "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}]}, "published": "2025-05-29T14:15:36.597", "references": [{"url": "https://git.kernel.org/stable/c/61e0fc3312309867e5a3495329dad0286d2a5703", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/bbfe756dc3062c1e934f06e5ba39c239aa953b92", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/c26076197df348c84cc23e5962d61902e072a0f5", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "[email protected]", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/erofs/fileio: call erofs_onlinefolio_split() after bio_add_folio()\n\nIf bio_add_folio() fails (because it is full),\nerofs_fileio_scan_folio() needs to submit the I/O request via\nerofs_fileio_rq_submit() and allocate a new I/O request with an empty\n`struct bio`. Then it retries the bio_add_folio() call.\n\nHowever, at this point, erofs_onlinefolio_split() has already been\ncalled which increments `folio->private`; the retry will call\nerofs_onlinefolio_split() again, but there will never be a matching\nerofs_onlinefolio_end() call. This leaves the folio locked forever\nand all waiters will be stuck in folio_wait_bit_common().\n\nThis bug has been added by commit ce63cb62d794 (\"erofs: support\nunencoded inodes for fileio\"), but was practically unreachable because\nthere was room for 256 folios in the `struct bio` - until commit\n9f74ae8c9ac9 (\"erofs: shorten bvecs[] for file-backed mounts\") which\nreduced the array capacity to 16 folios.\n\nIt was now trivial to trigger the bug by manually invoking readahead\nfrom userspace, e.g.:\n\n posix_fadvise(fd, 0, st.st_size, POSIX_FADV_WILLNEED);\n\nThis should be fixed by invoking erofs_onlinefolio_split() only after\nbio_add_folio() has succeeded. This is safe: asynchronous completions\ninvoking erofs_onlinefolio_end() will not unlock the folio because\nerofs_fileio_scan_folio() is still holding a reference to be released\nby erofs_onlinefolio_end() at the end."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: fs/erofs/fileio: llamar a erofs_onlinefolio_split() despu\u00e9s de bio_add_folio(). Si bio_add_folio() falla (porque est\u00e1 lleno), erofs_fileio_scan_folio() debe enviar la solicitud de E/S mediante erofs_fileio_rq_submit() y asignar una nueva solicitud de E/S con un `struct bio` vac\u00edo. Luego, vuelve a intentar la llamada a bio_add_folio(). Sin embargo, en este punto, ya se ha llamado a erofs_onlinefolio_split(), lo que incrementa `folio->private`; el reintento llamar\u00e1 a erofs_onlinefolio_split() de nuevo, pero nunca habr\u00e1 una llamada erofs_onlinefolio_end() coincidente. Esto deja el folio bloqueado para siempre y todos los que esperan quedar\u00e1n atascados en folio_wait_bit_common(). Este error se a\u00f1adi\u00f3 con el commit ce63cb62d794 (\"erofs: compatibilidad con inodos no codificados para fileio\"), pero era pr\u00e1cticamente imposible de solucionar porque hab\u00eda espacio para 256 folios en la estructura `struct bio`, hasta el commit 9f74ae8c9ac9 (\"erofs: acortar bvecs[] para montajes con respaldo de archivo\"), que redujo la capacidad del array a 16 folios. Ahora era f\u00e1cil activar el error invocando manualmente la lectura anticipada desde el espacio de usuario, por ejemplo: posix_fadvise(fd, 0, st.st_size, POSIX_FADV_WILLNEED); Esto deber\u00eda solucionarse invocando erofs_onlinefolio_split() solo despu\u00e9s de que bio_add_folio() se haya ejecutado correctamente. Esto es seguro: las finalizaciones asincr\u00f3nicas que invocan erofs_onlinefolio_end() no desbloquear\u00e1n el folio porque erofs_fileio_scan_folio() todav\u00eda contiene una referencia que erofs_onlinefolio_end() liberar\u00e1 al final."}], "lastModified": "2025-11-14T16:48:01.300", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "69281F47-5478-4C16-818E-9DAC6D962CB6", "versionEndExcluding": "6.12.29", "versionStartIncluding": "6.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "5715A6F5-A34A-4B27-8A64-82825E963995", "versionEndExcluding": "6.14.7", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8D465631-2980-487A-8E65-40AE2B9F8ED1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4C9D071F-B28E-46EC-AC61-22B913390211"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "13FC0DDE-E513-465E-9E81-515702D49B74"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8C7B5B0E-4EEB-48F5-B4CF-0935A7633845"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc5:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "2D240580-3048-49B2-9E27-F115A9DF8224"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}