{"cve":"CVE-2025-22123","nvd":{"published":"2025-04-16T15:16:06.450","modified":"2026-06-17T08:45:11.890","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to avoid accessing uninitialized curseg\n\nsyzbot reports a f2fs bug as below:\n\nF2FS-fs (loop3): Stopped filesystem due to reason: 7\nkworker/u8:7: attempt to access beyond end of device\nBUG: unable to handle page fault for address: ffffed1604ea3dfa\nRIP: 0010:get_ckpt_valid_blocks fs/f2fs/segment.h:361 [inline]\nRIP: 0010:has_curseg_enough_space fs/f2fs/segment.h:570 [inline]\nRIP: 0010:__get_secs_required fs/f2fs/segment.h:620 [inline]\nRIP: 0010:has_not_enough_free_secs fs/f2fs/segment.h:633 [inline]\nRIP: 0010:has_enough_free_secs+0x575/0x1660 fs/f2fs/segment.h:649\n <TASK>\n f2fs_is_checkpoint_ready fs/f2fs/segment.h:671 [inline]\n f2fs_write_inode+0x425/0x540 fs/f2fs/inode.c:791\n write_inode fs/fs-writeback.c:1525 [inline]\n __writeback_single_inode+0x708/0x10d0 fs/fs-writeback.c:1745\n writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976\n wb_writeback+0x413/0xb80 fs/fs-writeback.c:2156\n wb_do_writeback fs/fs-writeback.c:2303 [inline]\n wb_workfn+0x410/0x1080 fs/fs-writeback.c:2343\n process_one_work kernel/workqueue.c:3236 [inline]\n process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317\n worker_thread+0x870/0xd30 kernel/workqueue.c:3398\n kthread+0x7a9/0x920 kernel/kthread.c:464\n ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244\n\nCommit 8b10d3653735 (\"f2fs: introduce FAULT_NO_SEGMENT\") allows to trigger\nno free segment fault in allocator, then it will update curseg->segno to\nNULL_SEGNO, though, CP_ERROR_FLAG has been set, f2fs_write_inode() missed\nto check the flag, and access invalid curseg->segno directly in below call\npath, then resulting in panic:\n\n- f2fs_write_inode\n - f2fs_is_checkpoint_ready\n  - has_enough_free_secs\n   - has_not_enough_free_secs\n    - __get_secs_required\n     - has_curseg_enough_space\n      - get_ckpt_valid_blocks\n      : access invalid curseg->segno\n\nTo avoid this issue, let's:\n- check CP_ERROR_FLAG flag in prior to f2fs_is_checkpoint_ready() in\nf2fs_write_inode().\n- in has_curseg_enough_space(), save curseg->segno into a temp variable,\nand verify its validation before use.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-908"],"references":["https://git.kernel.org/stable/c/7f90e5d423cd2d4c74b2abb527872f335108637f","https://git.kernel.org/stable/c/986c50f6bca109c6cf362b4e2babcb85aba958f6","https://git.kernel.org/stable/c/bf49527089ec1ba894c6e587affabbfb2329f52e"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:01:11.054312287+00:00"},"epss":{"cve":"CVE-2025-22123","score":0.00186,"percentile":0.08191,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}