CVE-2022-49771

{"id": "CVE-2022-49771", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "[email protected]", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.7, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.0}]}, "published": "2025-05-01T15:16:00.237", "references": [{"url": "https://git.kernel.org/stable/c/0c8d4112df329bf3dfbf27693f918c3b08676538", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/3a1c35d72dc0b34d1e746ed705790c0f630aa427", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/4fe1ec995483737f3d2a14c3fe1d8fe634972979", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/5398b8e275bf81a2517b327d216c0f37ac9ac5ae", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/6a818db0d5aecf80d4ba9e10ac153f60adc629ca", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/6ffce7a92ef5c68f7e5d6f4d722c2f96280c064b", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b545c0e1e4094d4de2bdfe9a3823f9154b0c0005", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/f59f5a269ca5e43c567aca7f1f52500a0186e9b7", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "[email protected]", "description": [{"lang": "en", "value": "CWE-362"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm ioctl: fix misbehavior if list_versions races with module loading\n\n__list_versions will first estimate the required space using the\n\"dm_target_iterate(list_version_get_needed, &needed)\" call and then will\nfill the space using the \"dm_target_iterate(list_version_get_info,\n&iter_info)\" call. Each of these calls locks the targets using the\n\"down_read(&_lock)\" and \"up_read(&_lock)\" calls, however between the first\nand second \"dm_target_iterate\" there is no lock held and the target\nmodules can be loaded at this point, so the second \"dm_target_iterate\"\ncall may need more space than what was the first \"dm_target_iterate\"\nreturned.\n\nThe code tries to handle this overflow (see the beginning of\nlist_version_get_info), however this handling is incorrect.\n\nThe code sets \"param->data_size = param->data_start + needed\" and\n\"iter_info.end = (char *)vers+len\" - \"needed\" is the size returned by the\nfirst dm_target_iterate call; \"len\" is the size of the buffer allocated by\nuserspace.\n\n\"len\" may be greater than \"needed\"; in this case, the code will write up\nto \"len\" bytes into the buffer, however param->data_size is set to\n\"needed\", so it may write data past the param->data_size value. The ioctl\ninterface copies only up to param->data_size into userspace, thus part of\nthe result will be truncated.\n\nFix this bug by setting \"iter_info.end = (char *)vers + needed;\" - this\nguarantees that the second \"dm_target_iterate\" call will write only up to\nthe \"needed\" buffer and it will exit with \"DM_BUFFER_FULL_FLAG\" if it\noverflows the \"needed\" space - in this case, userspace will allocate a\nlarger buffer and retry.\n\nNote that there is also a bug in list_version_get_needed - we need to add\n\"strlen(tt->name) + 1\" to the needed size, not \"strlen(tt->name)\"."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: dm ioctl: se corrige el comportamiento incorrecto si list_versions se acelera al cargar m\u00f3dulos. __list_versions primero estimar\u00e1 el espacio requerido mediante la llamada \"dm_target_iterate(list_version_get_needed, &needed)\" y luego llenar\u00e1 el espacio mediante la llamada \"dm_target_iterate(list_version_get_info, &iter_info)\". Cada una de estas llamadas bloquea los destinos mediante las llamadas \"down_read(&_lock)\" y \"up_read(&_lock)\". Sin embargo, entre la primera y la segunda llamada \"dm_target_iterate\" no se mantiene el bloqueo y los m\u00f3dulos de destino se pueden cargar en este punto, por lo que la segunda llamada \"dm_target_iterate\" podr\u00eda necesitar m\u00e1s espacio que el devuelto por la primera llamada \"dm_target_iterate\". El c\u00f3digo intenta gestionar este desbordamiento (v\u00e9ase el comienzo de list_version_get_info), pero esta gesti\u00f3n es incorrecta. El c\u00f3digo establece \"param->data_size = param->data_start + needed\" y \"iter_info.end = (char *)vers+len\": \"needed\" es el tama\u00f1o devuelto por la primera llamada a dm_target_iterate; \"len\" es el tama\u00f1o del b\u00fafer asignado por el espacio de usuario. \"len\" puede ser mayor que \"needed\"; en este caso, el c\u00f3digo escribir\u00e1 hasta \"len\" bytes en el b\u00fafer; sin embargo, param->data_size se establece en \"needed\", por lo que podr\u00eda escribir datos que superen el valor de param->data_size. La interfaz ioctl solo copia hasta param->data_size en el espacio de usuario, por lo que parte del resultado se truncar\u00e1. Corrija este error estableciendo \"iter_info.end = (char *)vers + needed;\" Esto garantiza que la segunda llamada \"dm_target_iterate\" solo escriba hasta el b\u00fafer necesario y finalice con \"DM_BUFFER_FULL_FLAG\" si se desborda dicho espacio. En este caso, el espacio de usuario asignar\u00e1 un b\u00fafer mayor y reintentar\u00e1. Tenga en cuenta que tambi\u00e9n hay un error en list_version_get_needed: debemos agregar \"strlen(tt->name) + 1\" al tama\u00f1o necesario, no \"strlen(tt->name)\"."}], "lastModified": "2025-11-07T18:25:22.217", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "65416FEB-3A76-4DA9-A96A-1479EC77AFB6", "versionEndExcluding": "4.9.334"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "424802D2-E9E7-48A9-AD6F-DF2227B3D83A", "versionEndExcluding": "4.14.300", "versionStartIncluding": "4.10"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "A5C69A12-68E2-400E-9A5A-375A673C8402", "versionEndExcluding": "4.19.267", "versionStartIncluding": "4.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "94D21814-3051-4860-AB06-C7880A3D4933", "versionEndExcluding": "5.4.225", "versionStartIncluding": "4.20"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E2152F3D-E6D3-405D-B0BE-911B8B6E2EE6", "versionEndExcluding": "5.10.156", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "51BBEF3B-79F5-4D4C-ADBA-F34DA0E2465C", "versionEndExcluding": "5.15.80", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "64F9ADD1-3ADB-4D66-A00F-4A83010B05F0", "versionEndExcluding": "6.0.10", "versionStartIncluding": "5.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.1:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E7E331DA-1FB0-4DEC-91AC-7DA69D461C11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.1:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "17F0B248-42CF-4AE6-A469-BB1BAE7F4705"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.1:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E2422816-0C14-4B5E-A1E6-A9D776E5C49B"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.1:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "1C6E00FE-5FB9-4D20-A1A1-5A32128F9B76"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.1:rc5:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "35B26BE4-43A6-4A36-A7F6-5B3F572D9186"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}