{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-54068", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-12-24T12:21:05.092Z", "datePublished": "2025-12-24T12:23:12.818Z", "dateUpdated": "2026-08-05T09:16:55.942Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T09:16:55.942Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: compress: fix to call f2fs_wait_on_page_writeback() in f2fs_write_raw_pages()\n\nBUG_ON() will be triggered when writing files concurrently,\nbecause the same page is writtenback multiple times.\n\n1597 void folio_end_writeback(struct folio *folio)\n1598 {\n\t\t......\n1618 if (!__folio_end_writeback(folio))\n1619 BUG();\n\t\t......\n1625 }\n\nkernel BUG at mm/filemap.c:1619!\nCall Trace:\n \n f2fs_write_end_io+0x1a0/0x370\n blk_update_request+0x6c/0x410\n blk_mq_end_request+0x15/0x130\n blk_complete_reqs+0x3c/0x50\n __do_softirq+0xb8/0x29b\n ? sort_range+0x20/0x20\n run_ksoftirqd+0x19/0x20\n smpboot_thread_fn+0x10b/0x1d0\n kthread+0xde/0x110\n ? kthread_complete_and_exit+0x20/0x20\n ret_from_fork+0x22/0x30\n \n\nBelow is the concurrency scenario:\n\n[Process A]\t\t[Process B]\t\t[Process C]\nf2fs_write_raw_pages()\n - redirty_page_for_writepage()\n - unlock page()\n\t\t\tf2fs_do_write_data_page()\n\t\t\t - lock_page()\n\t\t\t - clear_page_dirty_for_io()\n\t\t\t - set_page_writeback() [1st writeback]\n\t\t\t .....\n\t\t\t - unlock page()\n\n\t\t\t\t\t\tgeneric_perform_write()\n\t\t\t\t\t\t - f2fs_write_begin()\n\t\t\t\t\t\t - wait_for_stable_page()\n\n\t\t\t\t\t\t - f2fs_write_end()\n\t\t\t\t\t\t - set_page_dirty()\n\n - lock_page()\n - f2fs_do_write_data_page()\n - set_page_writeback() [2st writeback]\n\nThis problem was introduced by the previous commit 7377e853967b (\"f2fs:\ncompress: fix potential deadlock of compress file\"). All pagelocks were\nreleased in f2fs_write_raw_pages(), but whether the page was\nin the writeback state was ignored in the subsequent writing process.\nLet's fix it by waiting for the page to writeback before writing." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is reached through ordinary local file I/O on a compression-enabled f2fs inode — buffered write(2)/mmap dirtying plus fsync/sync_file_range driving writeback into `f2fs_write_raw_pages()` (fs/f2fs/compress.c:1456). No network or adjacent-network protocol handler touches this path.\nAC:L - The attacker owns every side of the race: one thread enters `f2fs_write_raw_pages()` (guaranteed by writing incompressible/partial-cluster data so `cluster_may_compress()` fails), a second thread issues concurrent writeback of the same page after it was redirtied and unlocked, and a third re-dirties the page via `generic_perform_write()`; the loop can be retried indefinitely, and the reporters hit it with ordinary concurrent file writes on shipping devices.\nPR:L - Only an unprivileged local account with write access to a file on an f2fs mount is needed — `f2fs_setflags_common()` lets any file owner set F2FS_COMPR_FL via FS_IOC_SETFLAGS, and `compress_extension=` mount options set it automatically for app files on Android /data. No capability check exists on the write, fsync, or writeback paths.\nUI:N - The attacker performs all three roles itself with its own threads on its own file; the f2fs volume is already mounted at boot on Android/embedded systems, so no victim action is required at any point.\nS:U - The damage is confined to kernel page-cache state, f2fs on-disk structures, and the kernel managing them — the same security authority. No VM, hypervisor, or IOMMU boundary is crossed.\nC:H - The first I/O completion clears PG_writeback while the second bio over the same page is still in flight, and PG_writeback is the only thing pinning a writeback page (`bio_add_page()` takes no reference), so the page can be truncated, reclaimed, and reused while the device still DMAs from it — writing arbitrary reused kernel page contents into the attacker's file blocks, which it can then read back.\nI:H - The same broken invariant makes `f2fs_write_end_io()` run `clear_page_private_gcing()`/`end_page_writeback()` on a folio that may already be freed and heap-sprayed, a write into reclaimed memory; additionally two concurrent out-of-place writes of the same page index race in `f2fs_update_data_blkaddr()`/`f2fs_invalidate_blocks()`, leaving stale or cross-linked blocks and persistent on-disk corruption requiring fsck.\nA:H - The documented outcome is `BUG()` at mm/filemap.c:1619 in `folio_end_writeback()` reached from `f2fs_write_end_io()` in softirq/block-completion context — a fatal exception in interrupt context that panics the machine, and on an Android or embedded device whose userdata is f2fs it is trivially repeatable." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/f2fs/compress.c" ], "versions": [ { "version": "4c8ff7095bef64fc47e996a938f7d57f9e077da3", "lessThan": "a8226a45b2a9ce83ba7a167a387a00fecc319e71", "status": "affected", "versionType": "git" }, { "version": "4c8ff7095bef64fc47e996a938f7d57f9e077da3", "lessThan": "169134da419cb8ffbe3b0743bc24573e16952ea9", "status": "affected", "versionType": "git" }, { "version": "4c8ff7095bef64fc47e996a938f7d57f9e077da3", "lessThan": "6604df2a9d07ba8f8fb1ac14046c2c83776faa4f", "status": "affected", "versionType": "git" }, { "version": "4c8ff7095bef64fc47e996a938f7d57f9e077da3", "lessThan": "9940877c4fe752923a53f0f7372f2f152b6eccf0", "status": "affected", "versionType": "git" }, { "version": "4c8ff7095bef64fc47e996a938f7d57f9e077da3", "lessThan": "ad31eed06c3b4d63b2d38322a271d4009aee4bb3", "status": "affected", "versionType": "git" }, { "version": "4c8ff7095bef64fc47e996a938f7d57f9e077da3", "lessThan": "babedcbac164cec970872b8097401ca913a80e61", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/f2fs/compress.c" ], "versions": [ { "version": "5.6", "status": "affected" }, { "version": "0", "lessThan": "5.6", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.180", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.111", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.28", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.2.15", "lessThanOrEqual": "6.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.3.2", "lessThanOrEqual": "6.3.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.4", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "5.10.180" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "5.15.111" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.1.28" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.2.15" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.3.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.4" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/a8226a45b2a9ce83ba7a167a387a00fecc319e71" }, { "url": "https://git.kernel.org/stable/c/169134da419cb8ffbe3b0743bc24573e16952ea9" }, { "url": "https://git.kernel.org/stable/c/6604df2a9d07ba8f8fb1ac14046c2c83776faa4f" }, { "url": "https://git.kernel.org/stable/c/9940877c4fe752923a53f0f7372f2f152b6eccf0" }, { "url": "https://git.kernel.org/stable/c/ad31eed06c3b4d63b2d38322a271d4009aee4bb3" }, { "url": "https://git.kernel.org/stable/c/babedcbac164cec970872b8097401ca913a80e61" } ], "title": "f2fs: compress: fix to call f2fs_wait_on_page_writeback() in f2fs_write_raw_pages()", "x_generator": { "engine": "bippy-1.2.0" } } } }