CVE-2021-47114

{"id": "CVE-2021-47114", "cveTags": [], "metrics": {"cvssMetricV31": [{"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": "2024-03-15T21:15:06.723", "references": [{"url": "https://git.kernel.org/stable/c/0a31dd6fd2f4e7db538fb6eb1f06973d81f8dd3b", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/33e03adafb29eedae1bae9cdb50c1385279fcf65", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/624fa7baa3788dc9e57840ba5b94bc22b03cda57", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/6bba4471f0cc1296fe3c2089b9e52442d3074b2e", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/a1700479524bb9cb5e8ae720236a6fabd003acae", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/c8d5faee46242c3f33b8a71a4d7d52214785bfcc", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/cc2edb99ea606a45182b5ea38cc8f4e583aa0774", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/cec4e857ffaa8c447f51cd8ab4e72350077b6770", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/0a31dd6fd2f4e7db538fb6eb1f06973d81f8dd3b", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/33e03adafb29eedae1bae9cdb50c1385279fcf65", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/624fa7baa3788dc9e57840ba5b94bc22b03cda57", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/6bba4471f0cc1296fe3c2089b9e52442d3074b2e", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/a1700479524bb9cb5e8ae720236a6fabd003acae", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/c8d5faee46242c3f33b8a71a4d7d52214785bfcc", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/cc2edb99ea606a45182b5ea38cc8f4e583aa0774", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/cec4e857ffaa8c447f51cd8ab4e72350077b6770", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}], "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\nocfs2: fix data corruption by fallocate\n\nWhen fallocate punches holes out of inode size, if original isize is in\nthe middle of last cluster, then the part from isize to the end of the\ncluster will be zeroed with buffer write, at that time isize is not yet\nupdated to match the new size, if writeback is kicked in, it will invoke\nocfs2_writepage()->block_write_full_page() where the pages out of inode\nsize will be dropped. That will cause file corruption. Fix this by\nzero out eof blocks when extending the inode size.\n\nRunning the following command with qemu-image 4.2.1 can get a corrupted\ncoverted image file easily.\n\n qemu-img convert -p -t none -T none -f qcow2 $qcow_image \\\n -O qcow2 -o compat=1.1 $qcow_image.conv\n\nThe usage of fallocate in qemu is like this, it first punches holes out\nof inode size, then extend the inode size.\n\n fallocate(11, FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 2276196352, 65536) = 0\n fallocate(11, 0, 2276196352, 65536) = 0\n\nv1: https://www.spinics.net/lists/linux-fsdevel/msg193999.html\nv2: https://lore.kernel.org/linux-fsdevel/[email protected]/T/"}, {"lang": "es", "value": "En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: ocfs2: corrige la corrupci\u00f3n de datos por fallocate Cuando fallocate perfora agujeros en el tama\u00f1o del inodo, si el isize original est\u00e1 en el medio del \u00faltimo cl\u00faster, entonces la parte desde isize hasta el final del cl\u00faster se pondr\u00e1 a cero con la escritura en el b\u00fafer, en ese momento isize a\u00fan no se ha actualizado para que coincida con el nuevo tama\u00f1o, si se activa la reescritura, invocar\u00e1 ocfs2_writepage()->block_write_full_page() donde se eliminar\u00e1n las p\u00e1ginas fuera del tama\u00f1o del inodo. Eso causar\u00e1 corrupci\u00f3n de archivos. Solucione este problema poniendo a cero los bloques eof al extender el tama\u00f1o del inodo. Ejecutar el siguiente comando con qemu-image 4.2.1 puede obtener f\u00e1cilmente un archivo de imagen corrupto y convertido. qemu-img convert -p -t none -T none -f qcow2 $qcow_image \\ -O qcow2 -o compat=1.1 $qcow_image.conv El uso de fallocate en qemu es as\u00ed, primero perfora agujeros en el tama\u00f1o del inodo, luego ampliar el tama\u00f1o del inodo. fallocate(11, FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 2276196352, 65536) = 0 fallocate(11, 0, 2276196352, 65536) = 0 v1: https://www.spinics.net/lists/linux-fsdevel/msg193999.html v2: https //lore.kernel.org/linux-fsdevel/[email protected]/T/"}], "lastModified": "2025-04-04T14:39:41.120", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "99854A18-73AB-4333-A59F-D4905B9A977B", "versionEndExcluding": "4.4.272"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8FEC5189-264E-4620-BD41-8B5E44F20D80", "versionEndExcluding": "4.9.272", "versionStartIncluding": "4.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "32BD3098-E25B-4893-87B7-49DAAD61B503", "versionEndExcluding": "4.14.236", "versionStartIncluding": "4.10"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "219AB3A3-BDC8-47F5-A638-4A3D5D451EC3", "versionEndExcluding": "4.19.194", "versionStartIncluding": "4.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "552FBD6A-793D-4EE1-9D44-69978256AA46", "versionEndExcluding": "5.4.125", "versionStartIncluding": "4.20"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "B2136BD5-4F86-40C8-96C8-5C90A015490C", "versionEndExcluding": "5.10.43", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "27384800-AB48-4C08-891E-34B66F5FC4AA", "versionEndExcluding": "5.12.10", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0CBAD0FC-C281-4666-AB2F-F8E6E1165DF7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "96AC23B2-D46A-49D9-8203-8E1BEDCA8532"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "DA610E30-717C-4700-9F77-A3C9244F3BFD"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "1ECD33F5-85BE-430B-8F86-8D7BD560311D"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}