CVE-2021-47638

{"id": "CVE-2021-47638", "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": "2025-02-26T06:37:05.580", "references": [{"url": "https://git.kernel.org/stable/c/14276d38c89a170363e90b6ac0a53c3cf61b87fc", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/2ad07009c459e56ebdcc089d850d664660fdb742", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/2b3236ecf96db7af5836e1366ce39ace8ce832fa", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/40a8f0d5e7b3999f096570edab71c345da812e3e", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/6d7a158a7363c1f6604aa47ae1a280a5c65123dd", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/8b3c7be16f3f4dfd6e15ac651484e59d3fa36274", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/a90e2dbe66d2647ff95a0442ad2e86482d977fd8", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b9a937f096e608b3368c1abc920d4d640ba2c94f", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "[email protected]", "description": [{"lang": "en", "value": "CWE-415"}]}, {"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "description": [{"lang": "en", "value": "CWE-415"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nubifs: rename_whiteout: Fix double free for whiteout_ui->data\n\n'whiteout_ui->data' will be freed twice if space budget fail for\nrename whiteout operation as following process:\n\nrename_whiteout\n dev = kmalloc\n whiteout_ui->data = dev\n kfree(whiteout_ui->data) // Free first time\n iput(whiteout)\n ubifs_free_inode\n kfree(ui->data)\t // Double free!\n\nKASAN reports:\n==================================================================\nBUG: KASAN: double-free or invalid-free in ubifs_free_inode+0x4f/0x70\nCall Trace:\n kfree+0x117/0x490\n ubifs_free_inode+0x4f/0x70 [ubifs]\n i_callback+0x30/0x60\n rcu_do_batch+0x366/0xac0\n __do_softirq+0x133/0x57f\n\nAllocated by task 1506:\n kmem_cache_alloc_trace+0x3c2/0x7a0\n do_rename+0x9b7/0x1150 [ubifs]\n ubifs_rename+0x106/0x1f0 [ubifs]\n do_syscall_64+0x35/0x80\n\nFreed by task 1506:\n kfree+0x117/0x490\n do_rename.cold+0x53/0x8a [ubifs]\n ubifs_rename+0x106/0x1f0 [ubifs]\n do_syscall_64+0x35/0x80\n\nThe buggy address belongs to the object at ffff88810238bed8 which\nbelongs to the cache kmalloc-8 of size 8\n==================================================================\n\nLet ubifs_free_inode() free 'whiteout_ui->data'. BTW, delete unused\nassignment 'whiteout_ui->data_len = 0', process 'ubifs_evict_inode()\n-> ubifs_jnl_delete_inode() -> ubifs_jnl_write_inode()' doesn't need it\n(because 'inc_nlink(whiteout)' won't be excuted by 'goto out_release',\n and the nlink of whiteout inode is 0)."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ubifs: rename_whiteout: Se corrige la doble liberaci\u00f3n para whiteout_ui->data 'whiteout_ui->data' se liberar\u00e1 dos veces si el presupuesto de espacio falla para la operaci\u00f3n de cambio de nombre de whiteout como el siguiente proceso: rename_whiteout dev = kmalloc whiteout_ui->data = dev kfree(whiteout_ui->data) // Libera la primera vez iput(whiteout) ubifs_free_inode kfree(ui->data) // \u00a1Doble liberaci\u00f3n! KASAN informa: ==================================================================== ERROR: KASAN: liberaci\u00f3n doble o liberaci\u00f3n no v\u00e1lida en ubifs_free_inode+0x4f/0x70 Seguimiento de llamadas: kfree+0x117/0x490 ubifs_free_inode+0x4f/0x70 [ubifs] i_callback+0x30/0x60 rcu_do_batch+0x366/0xac0 __do_softirq+0x133/0x57f Asignado por la tarea 1506: kmem_cache_alloc_trace+0x3c2/0x7a0 do_rename+0x9b7/0x1150 [ubifs] ubifs_rename+0x106/0x1f0 [ubifs] do_syscall_64+0x35/0x80 Liberado por la tarea 1506: kfree+0x117/0x490 do_rename.cold+0x53/0x8a [ubifs] ubifs_rename+0x106/0x1f0 [ubifs] do_syscall_64+0x35/0x80 La direcci\u00f3n con errores pertenece al objeto en ffff88810238bed8 que pertenece al cach\u00e9 kmalloc-8 de tama\u00f1o 8 ===================================================================== Deje que ubifs_free_inode() libere 'whiteout_ui->data'. Por cierto, elimine la asignaci\u00f3n no utilizada 'whiteout_ui->data_len = 0', el proceso 'ubifs_evict_inode() -> ubifs_jnl_delete_inode() -> ubifs_jnl_write_inode()' no lo necesita (porque 'inc_nlink(whiteout)' no ser\u00e1 ejecutado por 'goto out_release', y el nlink del inodo whiteout es 0)."}], "lastModified": "2025-10-01T20:15:40.810", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "EA8D1234-835A-47E7-8014-55948757E778", "versionEndExcluding": "4.14.276", "versionStartIncluding": "4.9"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "FA28527A-11D3-41D2-9C4C-ECAC0D6A4A2D", "versionEndExcluding": "4.19.238", "versionStartIncluding": "4.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8CB6E8F5-C2B1-46F3-A807-0F6104AC340F", "versionEndExcluding": "5.4.189", "versionStartIncluding": "4.20"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "91D3BFD0-D3F3-4018-957C-96CCBF357D79", "versionEndExcluding": "5.10.110", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "27C42AE8-B387-43E2-938A-E1C8B40BE6D5", "versionEndExcluding": "5.15.33", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "20C43679-0439-405A-B97F-685BEE50613B", "versionEndExcluding": "5.16.19", "versionStartIncluding": "5.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "210C679C-CF84-44A3-8939-E629C87E54BF", "versionEndExcluding": "5.17.2", "versionStartIncluding": "5.17"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}