CVE-2022-50067

{"id": "CVE-2022-50067", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "[email protected]", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 1.8}]}, "published": "2025-06-18T11:15:35.490", "references": [{"url": "https://git.kernel.org/stable/c/5d741afed0bac206640cc64d77b97853283cf719", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/78f8c2370e3d33e35f23bdc648653d779aeacb6e", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/85f02d6c856b9f3a0acf5219de6e32f58b9778eb", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/8e546674031fc1576da501e27a8fd165222e5a37", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b60e862e133f646f19023ece1d476d630a660de1", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/dcb11fe0a0a9cca2b7425191b9bf30dc29f2ad0f", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/ff0e8ed8dfb584575cffc1561f17a1d094e8565b", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "[email protected]", "description": [{"lang": "en", "value": "CWE-416"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: unset reloc control if transaction commit fails in prepare_to_relocate()\n\nIn btrfs_relocate_block_group(), the rc is allocated. Then\nbtrfs_relocate_block_group() calls\n\nrelocate_block_group()\n prepare_to_relocate()\n set_reloc_control()\n\nthat assigns rc to the variable fs_info->reloc_ctl. When\nprepare_to_relocate() returns, it calls\n\nbtrfs_commit_transaction()\n btrfs_start_dirty_block_groups()\n btrfs_alloc_path()\n kmem_cache_zalloc()\n\nwhich may fail for example (or other errors could happen). When the\nfailure occurs, btrfs_relocate_block_group() detects the error and frees\nrc and doesn't set fs_info->reloc_ctl to NULL. After that, in\nbtrfs_init_reloc_root(), rc is retrieved from fs_info->reloc_ctl and\nthen used, which may cause a use-after-free bug.\n\nThis possible bug can be triggered by calling btrfs_ioctl_balance()\nbefore calling btrfs_ioctl_defrag().\n\nTo fix this possible bug, in prepare_to_relocate(), check if\nbtrfs_commit_transaction() fails. If the failure occurs,\nunset_reloc_control() is called to set fs_info->reloc_ctl to NULL.\n\nThe error log in our fault-injection testing is shown as follows:\n\n [ 58.751070] BUG: KASAN: use-after-free in btrfs_init_reloc_root+0x7ca/0x920 [btrfs]\n ...\n [ 58.753577] Call Trace:\n ...\n [ 58.755800] kasan_report+0x45/0x60\n [ 58.756066] btrfs_init_reloc_root+0x7ca/0x920 [btrfs]\n [ 58.757304] record_root_in_trans+0x792/0xa10 [btrfs]\n [ 58.757748] btrfs_record_root_in_trans+0x463/0x4f0 [btrfs]\n [ 58.758231] start_transaction+0x896/0x2950 [btrfs]\n [ 58.758661] btrfs_defrag_root+0x250/0xc00 [btrfs]\n [ 58.759083] btrfs_ioctl_defrag+0x467/0xa00 [btrfs]\n [ 58.759513] btrfs_ioctl+0x3c95/0x114e0 [btrfs]\n ...\n [ 58.768510] Allocated by task 23683:\n [ 58.768777] ____kasan_kmalloc+0xb5/0xf0\n [ 58.769069] __kmalloc+0x227/0x3d0\n [ 58.769325] alloc_reloc_control+0x10a/0x3d0 [btrfs]\n [ 58.769755] btrfs_relocate_block_group+0x7aa/0x1e20 [btrfs]\n [ 58.770228] btrfs_relocate_chunk+0xf1/0x760 [btrfs]\n [ 58.770655] __btrfs_balance+0x1326/0x1f10 [btrfs]\n [ 58.771071] btrfs_balance+0x3150/0x3d30 [btrfs]\n [ 58.771472] btrfs_ioctl_balance+0xd84/0x1410 [btrfs]\n [ 58.771902] btrfs_ioctl+0x4caa/0x114e0 [btrfs]\n ...\n [ 58.773337] Freed by task 23683:\n ...\n [ 58.774815] kfree+0xda/0x2b0\n [ 58.775038] free_reloc_control+0x1d6/0x220 [btrfs]\n [ 58.775465] btrfs_relocate_block_group+0x115c/0x1e20 [btrfs]\n [ 58.775944] btrfs_relocate_chunk+0xf1/0x760 [btrfs]\n [ 58.776369] __btrfs_balance+0x1326/0x1f10 [btrfs]\n [ 58.776784] btrfs_balance+0x3150/0x3d30 [btrfs]\n [ 58.777185] btrfs_ioctl_balance+0xd84/0x1410 [btrfs]\n [ 58.777621] btrfs_ioctl+0x4caa/0x114e0 [btrfs]\n ..."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: btrfs: anular el control de reubicaci\u00f3n si falla el commit de la transacci\u00f3n en prepare_to_relocate(). En btrfs_relocate_block_group(), se asigna el rc. Luego, btrfs_relocate_block_group() llama a relocate_block_group() prepare_to_relocate() set_reloc_control() que asigna rc a la variable fs_info->reloc_ctl. Cuando prepare_to_relocate() retorna, llama a btrfs_commit_transaction() btrfs_start_dirty_block_groups() btrfs_alloc_path() kmem_cache_zalloc() que puede fallar, por ejemplo (o podr\u00edan ocurrir otros errores). Cuando ocurre el fallo, btrfs_relocate_block_group() detecta el error y libera rc y no establece fs_info->reloc_ctl en NULL. Posteriormente, en btrfs_init_reloc_root(), se recupera rc de fs_info->reloc_ctl y se utiliza, lo que podr\u00eda causar un error de Use-After-Free. Este posible error se puede activar llamando a btrfs_ioctl_balance() antes de llamar a btrfs_ioctl_defrag(). Para corregir este posible error, en prepare_to_relocate(), compruebe si btrfs_commit_transaction() falla. Si falla, se llama a unset_reloc_control() para establecer fs_info->reloc_ctl en NULL. El registro de errores en nuestras pruebas de inyecci\u00f3n de fallas se muestra a continuaci\u00f3n: [ 58.751070] ERROR: KASAN: use-after-free en btrfs_init_reloc_root+0x7ca/0x920 [btrfs] ... [ 58.753577] Seguimiento de llamadas: ... [ 58.755800] kasan_report+0x45/0x60 [ 58.756066] btrfs_init_reloc_root+0x7ca/0x920 [btrfs] [ 58.757304] record_root_in_trans+0x792/0xa10 [btrfs] [ 58.757748] btrfs_record_root_in_trans+0x463/0x4f0 [btrfs] [ 58.758231] start_transaction+0x896/0x2950 [btrfs] [ 58.758661] btrfs_defrag_root+0x250/0xc00 [btrfs] [ 58.759083] btrfs_ioctl_defrag+0x467/0xa00 [btrfs] [ 58.759513] btrfs_ioctl+0x3c95/0x114e0 [btrfs] ... [ 58.768510] Asignado por la tarea 23683: [ 58.768777] ____kasan_kmalloc+0xb5/0xf0 [ 58.769069] __kmalloc+0x227/0x3d0 [ 58.769325] alloc_reloc_control+0x10a/0x3d0 [btrfs] [ 58.769755] btrfs_relocate_block_group+0x7aa/0x1e20 [btrfs] [ 58.770228] btrfs_relocate_chunk+0xf1/0x760 [btrfs] [ 58.770655] __btrfs_balance+0x1326/0x1f10 [btrfs] [ 58.771071] btrfs_balance+0x3150/0x3d30 [btrfs] [ 58.771472] btrfs_ioctl_balance+0xd84/0x1410 [btrfs] [ 58.771902] btrfs_ioctl+0x4caa/0x114e0 [btrfs] ... [ 58.773337] Liberado por la tarea 23683: ... [ 58.774815] kfree+0xda/0x2b0 [ 58.775038] free_reloc_control+0x1d6/0x220 [btrfs] [ 58.775465] btrfs_relocate_block_group+0x115c/0x1e20 [btrfs] [ 58.775944] btrfs_relocate_chunk+0xf1/0x760 [btrfs] [ 58.776369] __btrfs_balance+0x1326/0x1f10 [btrfs] [ 58.776784] btrfs_balance+0x3150/0x3d30 [btrfs] [ 58.777185] btrfs_ioctl_balance+0xd84/0x1410 [btrfs] [ 58.777621] btrfs_ioctl+0x4caa/0x114e0 [btrfs] ..."}], "lastModified": "2025-11-17T18:25:37.337", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "042D6334-1740-4B6A-A505-BF529664A969", "versionEndExcluding": "4.14.318"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C6613E97-CA9E-4956-A888-2065F3C61304", "versionEndExcluding": "4.19.286", "versionStartIncluding": "4.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F1B2E171-8F3C-474F-B25A-F9110189E950", "versionEndExcluding": "5.4.247", "versionStartIncluding": "4.20"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "DEDF9E01-A66D-486E-A184-7E8EF9C25EF9", "versionEndExcluding": "5.10.184", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D5744A03-DA40-4A78-9063-13179361DC6D", "versionEndExcluding": "5.15.63", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0E669300-DA42-4ACD-86D8-68BE5F29FB88", "versionEndExcluding": "5.19.4", "versionStartIncluding": "5.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.0:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E8BD11A3-8643-49B6-BADE-5029A0117325"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}