CVE-2024-47689

{"id": "CVE-2024-47689", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.3, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/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": 1.6}]}, "published": "2024-10-21T12:15:05.733", "references": [{"url": "https://git.kernel.org/stable/c/1f63f405c1a1a64b9c310388aad7055fb86b245c", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/649ec8b30df113042588bd3d3cd4e98bcb1091e0", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/930c6ab93492c4b15436524e704950b364b2930c", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/de43021c72993877a8f86f9fddfa0687609da5a4", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-362"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to don't set SB_RDONLY in f2fs_handle_critical_error()\n\nsyzbot reports a f2fs bug as below:\n\n------------[ cut here ]------------\nWARNING: CPU: 1 PID: 58 at kernel/rcu/sync.c:177 rcu_sync_dtor+0xcd/0x180 kernel/rcu/sync.c:177\nCPU: 1 UID: 0 PID: 58 Comm: kworker/1:2 Not tainted 6.10.0-syzkaller-12562-g1722389b0d86 #0\nWorkqueue: events destroy_super_work\nRIP: 0010:rcu_sync_dtor+0xcd/0x180 kernel/rcu/sync.c:177\nCall Trace:\n percpu_free_rwsem+0x41/0x80 kernel/locking/percpu-rwsem.c:42\n destroy_super_work+0xec/0x130 fs/super.c:282\n process_one_work kernel/workqueue.c:3231 [inline]\n process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312\n worker_thread+0x86d/0xd40 kernel/workqueue.c:3390\n kthread+0x2f0/0x390 kernel/kthread.c:389\n ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244\n\nAs Christian Brauner pointed out [1]: the root cause is f2fs sets\nSB_RDONLY flag in internal function, rather than setting the flag\ncovered w/ sb->s_umount semaphore via remount procedure, then below\nrace condition causes this bug:\n\n- freeze_super()\n - sb_wait_write(sb, SB_FREEZE_WRITE)\n - sb_wait_write(sb, SB_FREEZE_PAGEFAULT)\n - sb_wait_write(sb, SB_FREEZE_FS)\n\t\t\t\t\t- f2fs_handle_critical_error\n\t\t\t\t\t - sb->s_flags |= SB_RDONLY\n- thaw_super\n - thaw_super_locked\n - sb_rdonly() is true, so it skips\n sb_freeze_unlock(sb, SB_FREEZE_FS)\n - deactivate_locked_super\n\nSince f2fs has almost the same logic as ext4 [2] when handling critical\nerror in filesystem if it mounts w/ errors=remount-ro option:\n- set CP_ERROR_FLAG flag which indicates filesystem is stopped\n- record errors to superblock\n- set SB_RDONLY falg\nOnce we set CP_ERROR_FLAG flag, all writable interfaces can detect the\nflag and stop any further updates on filesystem. So, it is safe to not\nset SB_RDONLY flag, let's remove the logic and keep in line w/ ext4 [3].\n\n[1] https://lore.kernel.org/all/20240729-himbeeren-funknetz-96e62f9c7aee@brauner\n[2] https://lore.kernel.org/all/20240729132721.hxih6ehigadqf7wx@quack3\n[3] https://lore.kernel.org/linux-ext4/20240805201241.27286-1-jack@suse.cz"}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: f2fs: correcci\u00f3n para no establecer SB_RDONLY en f2fs_handle_critical_error() syzbot informa un error de f2fs como se muestra a continuaci\u00f3n: ------------[ cortar aqu\u00ed ]------------ ADVERTENCIA: CPU: 1 PID: 58 en kernel/rcu/sync.c:177 rcu_sync_dtor+0xcd/0x180 kernel/rcu/sync.c:177 CPU: 1 UID: 0 PID: 58 Comm: kworker/1:2 No contaminado 6.10.0-syzkaller-12562-g1722389b0d86 #0 Cola de trabajo: eventos destroy_super_work RIP: 0010:rcu_sync_dtor+0xcd/0x180 kernel/rcu/sync.c:177 Rastreo de llamadas: percpu_free_rwsem+0x41/0x80 kernel/locking/percpu-rwsem.c:42 destroy_super_work+0xec/0x130 fs/super.c:282 process_one_work kernel/workqueue.c:3231 [en l\u00ednea] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Como cristiano Brauner se\u00f1al\u00f3 [1]: la causa ra\u00edz es que f2fs establece el indicador SB_RDONLY en la funci\u00f3n interna, en lugar de establecer el indicador cubierto con el sem\u00e1foro sb->s_umount a trav\u00e9s del procedimiento de remontaje, luego la siguiente condici\u00f3n de ejecuci\u00f3n causa este error: - freeze_super() - sb_wait_write(sb, SB_FREEZE_WRITE) - sb_wait_write(sb, SB_FREEZE_PAGEFAULT) - sb_wait_write(sb, SB_FREEZE_FS) - f2fs_handle_critical_error - sb->s_flags |= SB_RDONLY - thaw_super - thaw_super_locked - sb_rdonly() es verdadero, por lo que omite sb_freeze_unlock(sb, SB_FREEZE_FS) - deactivate_locked_super Dado que f2fs tiene casi la misma l\u00f3gica que ext4 [2] al manejar error cr\u00edtico en el sistema de archivos si se monta con la opci\u00f3n errors=remount-ro: - establecer el indicador CP_ERROR_FLAG que indica que el sistema de archivos est\u00e1 detenido - registrar errores en el superbloque - establecer el indicador SB_RDONLY Una vez que establecemos el indicador CP_ERROR_FLAG, todas las interfaces escribibles pueden detectar el indicador y detener cualquier actualizaci\u00f3n futura en el sistema de archivos. Por lo tanto, es seguro no establecer el indicador SB_RDONLY, eliminemos la l\u00f3gica y sigamos en l\u00ednea con ext4 [3]. [1] https://lore.kernel.org/all/20240729-himbeeren-funknetz-96e62f9c7aee@brauner [2] https://lore.kernel.org/all/20240729132721.hxih6ehigadqf7wx@quack3 [3] https://lore.kernel.org/linux-ext4/202408052 01241.27286-1-jack@suse.cz"}], "lastModified": "2024-10-23T15:53:06.410", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "3F74080D-0441-4EFD-AB4D-F8C72C720E7A", "versionEndExcluding": "6.5", "versionStartIncluding": "6.4.4"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "533A887F-F2B4-4445-8C73-11A8013D0A01", "versionEndExcluding": "6.6.54", "versionStartIncluding": "6.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "CE94BB8D-B0AB-4563-9ED7-A12122B56EBE", "versionEndExcluding": "6.10.13", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "AB755D26-97F4-43B6-8604-CD076811E181", "versionEndExcluding": "6.11.2", "versionStartIncluding": "6.11"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}