CVE-2024-42111

{"id": "CVE-2024-42111", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 6.3, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 5.2, "exploitabilityScore": 1.0}]}, "published": "2024-07-30T08:15:03.563", "references": [{"url": "https://git.kernel.org/stable/c/724d8042cef84496ddb4492dc120291f997ae26b", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/ebe5ea02577b2c527958af1b76ac472c7ab53a56", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/724d8042cef84496ddb4492dc120291f997ae26b", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/ebe5ea02577b2c527958af1b76ac472c7ab53a56", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-125"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: always do the basic checks for btrfs_qgroup_inherit structure\n\n[BUG]\nSyzbot reports the following regression detected by KASAN:\n\n BUG: KASAN: slab-out-of-bounds in btrfs_qgroup_inherit+0x42e/0x2e20 fs/btrfs/qgroup.c:3277\n Read of size 8 at addr ffff88814628ca50 by task syz-executor318/5171\n\n CPU: 0 PID: 5171 Comm: syz-executor318 Not tainted 6.10.0-rc2-syzkaller-00010-g2ab795141095 #0\n Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024\n Call Trace:\n <TASK>\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114\n print_address_description mm/kasan/report.c:377 [inline]\n print_report+0x169/0x550 mm/kasan/report.c:488\n kasan_report+0x143/0x180 mm/kasan/report.c:601\n btrfs_qgroup_inherit+0x42e/0x2e20 fs/btrfs/qgroup.c:3277\n create_pending_snapshot+0x1359/0x29b0 fs/btrfs/transaction.c:1854\n create_pending_snapshots+0x195/0x1d0 fs/btrfs/transaction.c:1922\n btrfs_commit_transaction+0xf20/0x3740 fs/btrfs/transaction.c:2382\n create_snapshot+0x6a1/0x9e0 fs/btrfs/ioctl.c:875\n btrfs_mksubvol+0x58f/0x710 fs/btrfs/ioctl.c:1029\n btrfs_mksnapshot+0xb5/0xf0 fs/btrfs/ioctl.c:1075\n __btrfs_ioctl_snap_create+0x387/0x4b0 fs/btrfs/ioctl.c:1340\n btrfs_ioctl_snap_create_v2+0x1f2/0x3a0 fs/btrfs/ioctl.c:1422\n btrfs_ioctl+0x99e/0xc60\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:907 [inline]\n __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n RIP: 0033:0x7fcbf1992509\n RSP: 002b:00007fcbf1928218 EFLAGS: 00000246 ORIG_RAX: 0000000000000010\n RAX: ffffffffffffffda RBX: 00007fcbf1a1f618 RCX: 00007fcbf1992509\n RDX: 0000000020000280 RSI: 0000000050009417 RDI: 0000000000000003\n RBP: 00007fcbf1a1f610 R08: 00007ffea1298e97 R09: 0000000000000000\n R10: 0000000000000000 R11: 0000000000000246 R12: 00007fcbf19eb660\n R13: 00000000200002b8 R14: 00007fcbf19e60c0 R15: 0030656c69662f2e\n </TASK>\n\nAnd it also pinned it down to commit b5357cb268c4 (\"btrfs: qgroup: do not\ncheck qgroup inherit if qgroup is disabled\").\n\n[CAUSE]\nThat offending commit skips the whole qgroup inherit check if qgroup is\nnot enabled.\n\nBut that also skips the very basic checks like\nnum_ref_copies/num_excl_copies and the structure size checks.\n\nMeaning if a qgroup enable/disable race is happening at the background,\nand we pass a btrfs_qgroup_inherit structure when the qgroup is\ndisabled, the check would be completely skipped.\n\nThen at the time of transaction commitment, qgroup is re-enabled and\nbtrfs_qgroup_inherit() is going to use the incorrect structure and\ncausing the above KASAN error.\n\n[FIX]\nMake btrfs_qgroup_check_inherit() only skip the source qgroup checks.\nSo that even if invalid btrfs_qgroup_inherit structure is passed in, we\ncan still reject invalid ones no matter if qgroup is enabled or not.\n\nFurthermore we do already have an extra safety inside\nbtrfs_qgroup_inherit(), which would just ignore invalid qgroup sources,\nso even if we only skip the qgroup source check we're still safe."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: btrfs: siempre haga las comprobaciones b\u00e1sicas de la estructura btrfs_qgroup_inherit [ERROR] Syzbot informa la siguiente regresi\u00f3n detectada por KASAN: ERROR: KASAN: slab-out-of-bounds in btrfs_qgroup_inherit+0x42e/ 0x2e20 fs/btrfs/qgroup.c:3277 Lectura de tama\u00f1o 8 en la direcci\u00f3n ffff88814628ca50 por tarea syz-executor318/5171 CPU: 0 PID: 5171 Comm: syz-executor318 No contaminado 6.10.0-rc2-syzkaller-00010-g2ab7951410 95 #0 Nombre del hardware: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/04/2024 Seguimiento de llamadas: __dump_stack lib/dump_stack.c:88 [en l\u00ednea] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm /kasan/report.c:377 [en l\u00ednea] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 btrfs_qgroup_inherit+0x42e/0x2e20 fs/btrfs/qgroup. c:3277 create_pending_snapshot+0x1359/0x29b0 fs/btrfs/transaction.c:1854 create_pending_snapshots+0x195/0x1d0 fs/btrfs/transaction.c:1922 btrfs_commit_transaction+0xf20/0x3740 fs/btrfs/transaction.c:23 82 create_snapshot+0x6a1/0x9e0 fs/btrfs/ioctl.c:875 btrfs_mksubvol+0x58f/0x710 fs/btrfs/ioctl.c:1029 btrfs_mksnapshot+0xb5/0xf0 fs/btrfs/ioctl.c:1075 __btrfs_ioctl_snap_create+0x387/0x4b0 fs/btrfs/ioctl.c: 1340 btrfs_ioctl_snap_create_v2+0x1f2/0x3a0 fs/btrfs/ioctl.c:1422 btrfs_ioctl+0x99e/0xc60 vfs_ioctl fs/ioctl.c:51 [en l\u00ednea] __do_sys_ioctl fs/ioctl.c:907 [en l\u00ednea] __se_sys_ioctl+0xfc/0x170 fs/ioctl .c:893 do_syscall_x64 arch/x86/entry/common.c:52 [en l\u00ednea] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 Entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcbf1992509 RSP: 002b:00007fcbf1928218 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fcbf1a1f618 RCX: 00007fcbf1992509 RDX: 0000000020000280 RSI: 0000000050 009417 RDI: 0000000000000003 RBP: 00007fcbf1a1f610 R08: 00007ffea1298e97 R09: 00000000000000000 R10: 0000000000000000 R11: 00000000000000 246 R12: 00007fcbf19eb660 R13: 00000000200002b8 R14: 00007fcbf19e60c0 R15: 0030656c69662f2e Y tambi\u00e9n lo fij\u00f3 para confirmar b5357cb268c4 (\"btrfs: qgroup: no marque la herencia de qgroup si qgroup est\u00e1 deshabilitado\"). [CAUSA] Esa confirmaci\u00f3n infractora omite toda la verificaci\u00f3n de herencia de qgroup si qgroup no est\u00e1 habilitado. Pero eso tambi\u00e9n omite las comprobaciones m\u00e1s b\u00e1sicas como num_ref_copies/num_excl_copies y las comprobaciones del tama\u00f1o de la estructura. Es decir, si se produce una carrera de habilitaci\u00f3n/deshabilitaci\u00f3n de qgroup en segundo plano y pasamos una estructura btrfs_qgroup_inherit cuando qgroup est\u00e1 deshabilitado, la verificaci\u00f3n se omitir\u00e1 por completo. Luego, en el momento del compromiso de la transacci\u00f3n, qgroup se vuelve a habilitar y btrfs_qgroup_inherit() utilizar\u00e1 la estructura incorrecta y provocar\u00e1 el error KASAN anterior. [FIX] Haga que btrfs_qgroup_check_inherit() solo omita las comprobaciones de qgroup de origen. De modo que incluso si se pasa una estructura btrfs_qgroup_inherit no v\u00e1lida, a\u00fan podemos rechazar las no v\u00e1lidas sin importar si qgroup est\u00e1 habilitado o no. Adem\u00e1s, ya tenemos una seguridad adicional dentro de btrfs_qgroup_inherit(), que simplemente ignorar\u00eda las fuentes de qgroup no v\u00e1lidas, por lo que incluso si solo nos saltamos la verificaci\u00f3n de la fuente de qgroup, todav\u00eda estamos a salvo."}], "lastModified": "2025-09-26T15:27:54.053", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "DD26A649-FB0B-4A7B-A16B-A9D27807D7E9", "versionEndExcluding": "6.9", "versionStartIncluding": "6.8.10"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "FAFB6233-53C7-4FBF-A477-12303637559F", "versionEndExcluding": "6.9.9", "versionStartIncluding": "6.9.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.9:-:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "3F2A4A3D-068A-4CF2-A09F-9C7937DDB0A5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.10:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "2EBB4392-5FA6-4DA9-9772-8F9C750109FA"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.10:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "331C2F14-12C7-45D5-893D-8C52EE38EA10"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.10:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "3173713D-909A-4DD3-9DD4-1E171EB057EE"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.10:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "79F18AFA-40F7-43F0-BA30-7BDB65F918B9"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.10:rc5:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "BD973AA4-A789-49BD-8D57-B2846935D3C7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.10:rc6:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8F3E9E0C-AC3E-4967-AF80-6483E8AB0078"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}