{"id":"CVE-2024-44942","state":"PUBLISHED","title":"f2fs: fix to do sanity check on F2FS_INLINE_DATA flag in inode during GC","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to do sanity check on F2FS_INLINE_DATA flag in inode during GC\n\nsyzbot reports a f2fs bug as below:\n\n------------[ cut here ]------------\nkernel BUG at fs/f2fs/inline.c:258!\nCPU: 1 PID: 34 Comm: kworker/u8:2 Not tainted 6.9.0-rc6-syzkaller-00012-g9e4bc4bcae01 #0\nRIP: 0010:f2fs_write_inline_data+0x781/0x790 fs/f2fs/inline.c:258\nCall Trace:\n f2fs_write_single_data_page+0xb65/0x1d60 fs/f2fs/data.c:2834\n f2fs_write_cache_pages fs/f2fs/data.c:3133 [inline]\n __f2fs_write_data_pages fs/f2fs/data.c:3288 [inline]\n f2fs_write_data_pages+0x1efe/0x3a90 fs/f2fs/data.c:3315\n do_writepages+0x35b/0x870 mm/page-writeback.c:2612\n __writeback_single_inode+0x165/0x10b0 fs/fs-writeback.c:1650\n writeback_sb_inodes+0x905/0x1260 fs/fs-writeback.c:1941\n wb_writeback+0x457/0xce0 fs/fs-writeback.c:2117\n wb_do_writeback fs/fs-writeback.c:2264 [inline]\n wb_workfn+0x410/0x1090 fs/fs-writeback.c:2304\n process_one_work kernel/workqueue.c:3254 [inline]\n process_scheduled_works+0xa12/0x17c0 kernel/workqueue.c:3335\n worker_thread+0x86d/0xd70 kernel/workqueue.c:3416\n kthread+0x2f2/0x390 kernel/kthread.c:388\n ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244\n\nThe root cause is: inline_data inode can be fuzzed, so that there may\nbe valid blkaddr in its direct node, once f2fs triggers background GC\nto migrate the block, it will hit f2fs_bug_on() during dirty page\nwriteback.\n\nLet's add sanity check on F2FS_INLINE_DATA flag in inode during GC,\nso that, it can forbid migrating inline_data inode's data block for\nfixing.","publishedAt":"2024-08-26T11:20:46.478Z","updatedAt":"2026-10-30T12:19:09.788Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/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":"98e4da8ca301e062d79ae168c67e56f3c3de3ce4","status":"affected","lessThan":"54a8da38b70553b61e2265ee0f26d034349dde25","versionType":"git"},{"version":"98e4da8ca301e062d79ae168c67e56f3c3de3ce4","status":"affected","lessThan":"ae00e6536a2dd54b64b39e9a39548870cf835745","versionType":"git"},{"version":"98e4da8ca301e062d79ae168c67e56f3c3de3ce4","status":"affected","lessThan":"26c07775fb5dc74351d1c3a2bc3cdf609b03e49f","versionType":"git"},{"version":"98e4da8ca301e062d79ae168c67e56f3c3de3ce4","status":"affected","lessThan":"fc01008c92f40015aeeced94750855a7111b6929","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/gc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.8","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.47","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.10.6","status":"unaffected","lessThanOrEqual":"6.10.*","versionType":"semver"},{"version":"6.11","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/gc.c"]}],"references":["https://git.kernel.org/stable/c/54a8da38b70553b61e2265ee0f26d034349dde25","https://git.kernel.org/stable/c/ae00e6536a2dd54b64b39e9a39548870cf835745","https://git.kernel.org/stable/c/26c07775fb5dc74351d1c3a2bc3cdf609b03e49f","https://git.kernel.org/stable/c/fc01008c92f40015aeeced94750855a7111b6929"],"weaknesses":[],"ingestedAt":"2026-10-30T12:36:04.432Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/44xxx/CVE-2024-44942.json","commit":"db8103c5921aac81d5d90efcf3745980dafabf49","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-44942","state":"PUBLISHED","datePublished":"2024-08-26T11:20:46.478Z","dateUpdated":"2026-10-30T12:19:09.788Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-08-21T05:34:56.665Z"},"containers":{"cna":{"title":"f2fs: fix to do sanity check on F2FS_INLINE_DATA flag in inode during GC","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to do sanity check on F2FS_INLINE_DATA flag in inode during GC\n\nsyzbot reports a f2fs bug as below:\n\n------------[ cut here ]------------\nkernel BUG at fs/f2fs/inline.c:258!\nCPU: 1 PID: 34 Comm: kworker/u8:2 Not tainted 6.9.0-rc6-syzkaller-00012-g9e4bc4bcae01 #0\nRIP: 0010:f2fs_write_inline_data+0x781/0x790 fs/f2fs/inline.c:258\nCall Trace:\n f2fs_write_single_data_page+0xb65/0x1d60 fs/f2fs/data.c:2834\n f2fs_write_cache_pages fs/f2fs/data.c:3133 [inline]\n __f2fs_write_data_pages fs/f2fs/data.c:3288 [inline]\n f2fs_write_data_pages+0x1efe/0x3a90 fs/f2fs/data.c:3315\n do_writepages+0x35b/0x870 mm/page-writeback.c:2612\n __writeback_single_inode+0x165/0x10b0 fs/fs-writeback.c:1650\n writeback_sb_inodes+0x905/0x1260 fs/fs-writeback.c:1941\n wb_writeback+0x457/0xce0 fs/fs-writeback.c:2117\n wb_do_writeback fs/fs-writeback.c:2264 [inline]\n wb_workfn+0x410/0x1090 fs/fs-writeback.c:2304\n process_one_work kernel/workqueue.c:3254 [inline]\n process_scheduled_works+0xa12/0x17c0 kernel/workqueue.c:3335\n worker_thread+0x86d/0xd70 kernel/workqueue.c:3416\n kthread+0x2f2/0x390 kernel/kthread.c:388\n ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244\n\nThe root cause is: inline_data inode can be fuzzed, so that there may\nbe valid blkaddr in its direct node, once f2fs triggers background GC\nto migrate the block, it will hit f2fs_bug_on() during dirty page\nwriteback.\n\nLet's add sanity check on F2FS_INLINE_DATA flag in inode during GC,\nso that, it can forbid migrating inline_data inode's data block for\nfixing."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"98e4da8ca301e062d79ae168c67e56f3c3de3ce4","status":"affected","lessThan":"54a8da38b70553b61e2265ee0f26d034349dde25","versionType":"git"},{"version":"98e4da8ca301e062d79ae168c67e56f3c3de3ce4","status":"affected","lessThan":"ae00e6536a2dd54b64b39e9a39548870cf835745","versionType":"git"},{"version":"98e4da8ca301e062d79ae168c67e56f3c3de3ce4","status":"affected","lessThan":"26c07775fb5dc74351d1c3a2bc3cdf609b03e49f","versionType":"git"},{"version":"98e4da8ca301e062d79ae168c67e56f3c3de3ce4","status":"affected","lessThan":"fc01008c92f40015aeeced94750855a7111b6929","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/gc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.8","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.47","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.10.6","status":"unaffected","lessThanOrEqual":"6.10.*","versionType":"semver"},{"version":"6.11","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/gc.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/54a8da38b70553b61e2265ee0f26d034349dde25"},{"url":"https://git.kernel.org/stable/c/ae00e6536a2dd54b64b39e9a39548870cf835745"},{"url":"https://git.kernel.org/stable/c/26c07775fb5dc74351d1c3a2bc3cdf609b03e49f"},{"url":"https://git.kernel.org/stable/c/fc01008c92f40015aeeced94750855a7111b6929"}],"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 poisoned inode reaches `gc_data_segment()` only after a local mount of an attacker-supplied f2fs image via loop device or removable media, and the triggering GC/writeback activity is entirely local kernel work. There is no network or adjacent-network path into the f2fs garbage collector.\nAC:L - Setting `F2FS_INLINE_DATA` in the inode while leaving a valid blkaddr in its direct node is a direct on-disk edit, and `is_alive()` plus the phase-4 checks then pass deterministically; background GC is enabled by default and the attacker can size the image so free sections run low, forcing migration on demand. No race, timing, or memory-layout condition outside the attacker's control is involved.\nPR:L - An unprivileged local user gets the crafted image mounted through loop devices or desktop/kiosk/Android automounters (udisks2, systemd, vold), and no capability check exists on the GC or writeback path that follows. This matches how the repo scores equivalent f2fs on-disk validation bugs (CVE-2024-47690, CVE-2024-56692).\nUI:N - In the automount/loop scenario the attacker performs the mount itself and the background GC kthread plus the flusher worker drive the crash asynchronously. No separate victim action is required.\nS:U - The BUG_ON panic, the stuck page/node-page locks, and the corrupted inode block-pointer array all remain inside the kernel's own security authority and the mounted filesystem. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - On the non-`CONFIG_F2FS_CHECK_FS` path the WARN is non-fatal and the inode's `i_addr[]` array is replaced with attacker-chosen 32-bit values that f2fs subsequently dereferences as block addresses in `f2fs_get_dnode_of_data()`/`f2fs_map_blocks()`, allowing in-range blocks belonging to other files on the volume to be read back. The persisted metadata corruption therefore yields cross-file content disclosure, not merely a crash.\nI:H - `memcpy_from_page(inline_data_addr(inode, dn.inode_page), page, 0, MAX_INLINE_DATA(inode))` stomps roughly the whole `i_addr[]` block-pointer array of the inode with the contents of an unrelated data block the attacker controls, and `set_page_dirty(dn.inode_page)` writes that back to disk. The result is attacker-controlled corruption of filesystem metadata that the kernel only flags with `SBI_NEED_FSCK` rather than rejecting.\nA:H - With `CONFIG_F2FS_CHECK_FS` the reported failure is an outright `kernel BUG at fs/f2fs/inline.c:258` inside the writeback kworker, which dies holding the data page lock and the locked inode node page so every subsequent access to that inode and the bdi flusher deadlocks; without it the `WARN_ON` is fatal under `panic_on_warn` and otherwise repeats on every GC pass while marking the filesystem as needing fsck."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:19:09.788Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.6.47"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.10.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.11"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2024-44942","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-09-10T15:27:26.047934Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-09-12T17:33:04.269Z"}}]}}}