{"id":"CVE-2025-22123","state":"PUBLISHED","title":"f2fs: fix to avoid accessing uninitialized curseg","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.","publishedAt":"2025-04-16T14:13:07.213Z","updatedAt":"2026-05-11T21:13:24.817Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8b10d3653735e117bc1954ade80d75ad7b46b801","status":"affected","lessThan":"bf49527089ec1ba894c6e587affabbfb2329f52e","versionType":"git"},{"version":"8b10d3653735e117bc1954ade80d75ad7b46b801","status":"affected","lessThan":"7f90e5d423cd2d4c74b2abb527872f335108637f","versionType":"git"},{"version":"8b10d3653735e117bc1954ade80d75ad7b46b801","status":"affected","lessThan":"986c50f6bca109c6cf362b4e2babcb85aba958f6","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/inode.c","fs/f2fs/segment.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.9","versionType":"semver"},{"version":"6.12.33","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.14.2","status":"unaffected","lessThanOrEqual":"6.14.*","versionType":"semver"},{"version":"6.15","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/inode.c","fs/f2fs/segment.h"]}],"references":["https://git.kernel.org/stable/c/bf49527089ec1ba894c6e587affabbfb2329f52e","https://git.kernel.org/stable/c/7f90e5d423cd2d4c74b2abb527872f335108637f","https://git.kernel.org/stable/c/986c50f6bca109c6cf362b4e2babcb85aba958f6"],"weaknesses":[],"ingestedAt":"2026-10-29T20:08:39.238Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/22xxx/CVE-2025-22123.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-22123","state":"PUBLISHED","datePublished":"2025-04-16T14:13:07.213Z","dateUpdated":"2026-05-11T21:13:24.817Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-12-29T08:45:45.823Z"},"containers":{"cna":{"title":"f2fs: fix to avoid accessing uninitialized curseg","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8b10d3653735e117bc1954ade80d75ad7b46b801","status":"affected","lessThan":"bf49527089ec1ba894c6e587affabbfb2329f52e","versionType":"git"},{"version":"8b10d3653735e117bc1954ade80d75ad7b46b801","status":"affected","lessThan":"7f90e5d423cd2d4c74b2abb527872f335108637f","versionType":"git"},{"version":"8b10d3653735e117bc1954ade80d75ad7b46b801","status":"affected","lessThan":"986c50f6bca109c6cf362b4e2babcb85aba958f6","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/inode.c","fs/f2fs/segment.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.9","versionType":"semver"},{"version":"6.12.33","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.14.2","status":"unaffected","lessThanOrEqual":"6.14.*","versionType":"semver"},{"version":"6.15","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/inode.c","fs/f2fs/segment.h"]}],"references":[{"url":"https://git.kernel.org/stable/c/bf49527089ec1ba894c6e587affabbfb2329f52e"},{"url":"https://git.kernel.org/stable/c/7f90e5d423cd2d4c74b2abb527872f335108637f"},{"url":"https://git.kernel.org/stable/c/986c50f6bca109c6cf362b4e2babcb85aba958f6"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T21:13:24.817Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.12.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.14.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.15"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}