{"id":"CVE-2025-23132","state":"PUBLISHED","title":"f2fs: quota: fix to avoid warning in dquot_writeback_dquots()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: quota: fix to avoid warning in dquot_writeback_dquots()\n\nF2FS-fs (dm-59): checkpoint=enable has some unwritten data.\n\n------------[ cut here ]------------\nWARNING: CPU: 6 PID: 8013 at fs/quota/dquot.c:691 dquot_writeback_dquots+0x2fc/0x308\npc : dquot_writeback_dquots+0x2fc/0x308\nlr : f2fs_quota_sync+0xcc/0x1c4\nCall trace:\ndquot_writeback_dquots+0x2fc/0x308\nf2fs_quota_sync+0xcc/0x1c4\nf2fs_write_checkpoint+0x3d4/0x9b0\nf2fs_issue_checkpoint+0x1bc/0x2c0\nf2fs_sync_fs+0x54/0x150\nf2fs_do_sync_file+0x2f8/0x814\n__f2fs_ioctl+0x1960/0x3244\nf2fs_ioctl+0x54/0xe0\n__arm64_sys_ioctl+0xa8/0xe4\ninvoke_syscall+0x58/0x114\n\ncheckpoint and f2fs_remount may race as below, resulting triggering warning\nin dquot_writeback_dquots().\n\natomic write                                    remount\n                                                - do_remount\n                                                 - down_write(&sb->s_umount);\n                                                  - f2fs_remount\n- ioctl\n - f2fs_do_sync_file\n  - f2fs_sync_fs\n   - f2fs_write_checkpoint\n    - block_operations\n     - locked = down_read_trylock(&sbi->sb->s_umount)\n       : fail to lock due to the write lock was held by remount\n                                                 - up_write(&sb->s_umount);\n     - f2fs_quota_sync\n      - dquot_writeback_dquots\n       - WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount))\n       : trigger warning because s_umount lock was unlocked by remount\n\nIf checkpoint comes from mount/umount/remount/freeze/quotactl, caller of\ncheckpoint has already held s_umount lock, calling dquot_writeback_dquots()\nin the context should be safe.\n\nSo let's record task to sbi->umount_lock_holder, so that checkpoint can\nknow whether the lock has held in the context or not by checking current\nw/ it.\n\nIn addition, in order to not misrepresent caller of checkpoint, we should\nnot allow to trigger async checkpoint for those callers: mount/umount/remount/\nfreeze/quotactl.","publishedAt":"2025-04-16T14:13:13.697Z","updatedAt":"2026-10-21T12:36:19.341Z","severity":{"score":7,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"af033b2aa8a874fd5737fafe90d159136527b5b4","status":"affected","lessThan":"9ec535db9da76dafa05c89f8b58a0b1d7dddba1c","versionType":"git"},{"version":"af033b2aa8a874fd5737fafe90d159136527b5b4","status":"affected","lessThan":"d7acf0a6c87aa282c86a36dbaa2f92fda88c5884","versionType":"git"},{"version":"af033b2aa8a874fd5737fafe90d159136527b5b4","status":"affected","lessThan":"eb85c2410d6f581e957cd03a644ff6ddbe592af9","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/checkpoint.c","fs/f2fs/f2fs.h","fs/f2fs/super.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.20","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.20","versionType":"semver"},{"version":"6.12.114","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/checkpoint.c","fs/f2fs/f2fs.h","fs/f2fs/super.c"]}],"references":["https://git.kernel.org/stable/c/9ec535db9da76dafa05c89f8b58a0b1d7dddba1c","https://git.kernel.org/stable/c/d7acf0a6c87aa282c86a36dbaa2f92fda88c5884","https://git.kernel.org/stable/c/eb85c2410d6f581e957cd03a644ff6ddbe592af9"],"weaknesses":[],"ingestedAt":"2026-10-29T20:08:39.238Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/23xxx/CVE-2025-23132.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-23132","state":"PUBLISHED","datePublished":"2025-04-16T14:13:13.697Z","dateUpdated":"2026-10-21T12:36:19.341Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-01-11T14:28:41.511Z"},"containers":{"cna":{"title":"f2fs: quota: fix to avoid warning in dquot_writeback_dquots()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: quota: fix to avoid warning in dquot_writeback_dquots()\n\nF2FS-fs (dm-59): checkpoint=enable has some unwritten data.\n\n------------[ cut here ]------------\nWARNING: CPU: 6 PID: 8013 at fs/quota/dquot.c:691 dquot_writeback_dquots+0x2fc/0x308\npc : dquot_writeback_dquots+0x2fc/0x308\nlr : f2fs_quota_sync+0xcc/0x1c4\nCall trace:\ndquot_writeback_dquots+0x2fc/0x308\nf2fs_quota_sync+0xcc/0x1c4\nf2fs_write_checkpoint+0x3d4/0x9b0\nf2fs_issue_checkpoint+0x1bc/0x2c0\nf2fs_sync_fs+0x54/0x150\nf2fs_do_sync_file+0x2f8/0x814\n__f2fs_ioctl+0x1960/0x3244\nf2fs_ioctl+0x54/0xe0\n__arm64_sys_ioctl+0xa8/0xe4\ninvoke_syscall+0x58/0x114\n\ncheckpoint and f2fs_remount may race as below, resulting triggering warning\nin dquot_writeback_dquots().\n\natomic write                                    remount\n                                                - do_remount\n                                                 - down_write(&sb->s_umount);\n                                                  - f2fs_remount\n- ioctl\n - f2fs_do_sync_file\n  - f2fs_sync_fs\n   - f2fs_write_checkpoint\n    - block_operations\n     - locked = down_read_trylock(&sbi->sb->s_umount)\n       : fail to lock due to the write lock was held by remount\n                                                 - up_write(&sb->s_umount);\n     - f2fs_quota_sync\n      - dquot_writeback_dquots\n       - WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount))\n       : trigger warning because s_umount lock was unlocked by remount\n\nIf checkpoint comes from mount/umount/remount/freeze/quotactl, caller of\ncheckpoint has already held s_umount lock, calling dquot_writeback_dquots()\nin the context should be safe.\n\nSo let's record task to sbi->umount_lock_holder, so that checkpoint can\nknow whether the lock has held in the context or not by checking current\nw/ it.\n\nIn addition, in order to not misrepresent caller of checkpoint, we should\nnot allow to trigger async checkpoint for those callers: mount/umount/remount/\nfreeze/quotactl."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"af033b2aa8a874fd5737fafe90d159136527b5b4","status":"affected","lessThan":"9ec535db9da76dafa05c89f8b58a0b1d7dddba1c","versionType":"git"},{"version":"af033b2aa8a874fd5737fafe90d159136527b5b4","status":"affected","lessThan":"d7acf0a6c87aa282c86a36dbaa2f92fda88c5884","versionType":"git"},{"version":"af033b2aa8a874fd5737fafe90d159136527b5b4","status":"affected","lessThan":"eb85c2410d6f581e957cd03a644ff6ddbe592af9","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/checkpoint.c","fs/f2fs/f2fs.h","fs/f2fs/super.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.20","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.20","versionType":"semver"},{"version":"6.12.114","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/checkpoint.c","fs/f2fs/f2fs.h","fs/f2fs/super.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/9ec535db9da76dafa05c89f8b58a0b1d7dddba1c"},{"url":"https://git.kernel.org/stable/c/d7acf0a6c87aa282c86a36dbaa2f92fda88c5884"},{"url":"https://git.kernel.org/stable/c/eb85c2410d6f581e957cd03a644ff6ddbe592af9"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable path is entered purely through local syscalls against a mounted f2fs volume — `syncfs()`, `fsync()` or `__f2fs_ioctl()` reaching `f2fs_sync_fs` → `f2fs_issue_checkpoint` → `block_operations`. There is no remote or network-facing route into f2fs checkpointing.\nAC:H - The attacker can spam the checkpoint side at will, but `down_read_trylock(&sb->s_umount)` only fails while a *writer* holds the lock, and every writer (mount/remount/umount/freeze/quotaon-off/shutdown ioctl) is a CAP_SYS_ADMIN operation the unprivileged attacker cannot initiate; the lock must additionally be released or be tearing down quota within the narrow window before `dquot_writeback_dquots()`. That timing dependency on an administrative mount-state change is beyond the attacker's control.\nPR:L - The attacker-facing half needs no privilege at all — any local user with a file or fd on the f2fs mount can loop on `syncfs()`/`fsync()` to drive checkpoints, which is the case on every Android device where `/data` is f2fs with the `quota_ino` feature enabled by default. No capability, and no user namespace, is required on the triggering path.\nUI:N - The attacker issues the triggering syscall themselves and nothing must be opened, mounted or clicked on their behalf. The concurrent administrative remount is a timing precondition already accounted for in Attack Complexity, not victim participation in the attack.\nS:U - The damage is confined to kernel memory and kernel-managed quota/filesystem state within the same security authority. No hypervisor, IOMMU or sandbox boundary is crossed.\nC:H - Running `dquot_writeback_dquots()`/`f2fs_quota_sync_file()` without `s_umount` removes exactly the protection that keeps quota state alive — `dqopt->files[type]->i_mapping` is dereferenced after only a lockless `sb_has_quota_active()` check, and `dqopt->info[cnt].dqi_dirty_list` is walked while `invalidate_dquots()` frees its entries. A use-after-free read of `struct inode`/`struct dquot` in a general-purpose slab is leverageable for disclosure of adjacent kernel objects.\nI:H - The same unsynchronized window lets `filemap_fdatawrite()` and `dquot_write_dquot()` write through a quota inode that `vfs_cleanup_quota_inode()` has already `iput()`ed and NULLed, giving a write into freed slab memory alongside corruption of on-disk quota accounting (f2fs flags `SBI_QUOTA_NEED_REPAIR`, requiring fsck). A use-after-free write is a classic route to control-flow hijack.\nA:H - The immediate, reported effect is a `WARNING` splat that taints the kernel and is an outright panic on the many hardened Android, cloud and embedded builds that set `panic_on_warn=1`. Beyond that, the lost lock readily oopses the kernel via NULL dereference of a cleared `dqopt->files[type]` or a use-after-free on the quota inode."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-21T12:36:19.341Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.12.114"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.14.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.15"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2025-23132","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-15T21:44:37.526409Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-15T21:51:58.276Z"}}]}}}