{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-53804", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-12-08T23:58:35.276Z", "datePublished": "2025-12-09T00:01:01.787Z", "dateUpdated": "2026-08-05T09:16:07.269Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T09:16:07.269Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: fix use-after-free bug of nilfs_root in nilfs_evict_inode()\n\nDuring unmount process of nilfs2, nothing holds nilfs_root structure after\nnilfs2 detaches its writer in nilfs_detach_log_writer(). However, since\nnilfs_evict_inode() uses nilfs_root for some cleanup operations, it may\ncause use-after-free read if inodes are left in \"garbage_list\" and\nreleased by nilfs_dispose_list() at the end of nilfs_detach_log_writer().\n\nFix this issue by modifying nilfs_evict_inode() to only clear inode\nwithout additional metadata changes that use nilfs_root if the file system\nis degraded to read-only or the writer is detached." } ], "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 flaw is reached only through a locally mounted nilfs2 volume — attacker-supplied on-disk metadata plus ordinary local file syscalls and the unmount path; nothing in fs/nilfs2 parses data from a remote peer.\nAC:L - The attacker fully authors the on-disk image, so the `__nilfs_error()`→`SB_RDONLY` degeneration and the resulting `-EROFS` bail in `nilfs_segctor_do_construct()` are deterministic, and the free-then-use ordering inside `nilfs_detach_log_writer()` is a fixed code sequence rather than a race; syzbot reproduced it reliably.\nPR:L - An unprivileged local desktop/kiosk user is enough: udisks2/polkit lets an active local session mount and eject removable media without a password, and the writes that strand inodes on `ns_dirty_files` are ordinary unprivileged VFS operations — matching the PR:L assigned to the same-family nilfs2 crafted-image CVEs.\nUI:N - On an auto-mounting host the attacker performs every step themselves — supply the image, dirty the inodes, trigger the eject/unmount — so no action by a separate victim is required.\nS:U - The freed `nilfs_root` and `ifile` objects and any resulting corruption stay entirely within the kernel's own security authority; no hypervisor, IOMMU, or sandbox boundary is crossed.\nC:H - After `kfree(root)`, `nilfs_evict_inode()` reads `ii->i_root->ifile` from a reclaimable general-purpose slab object and passes it to `nilfs_ifile_get_inode_block()`/`nilfs_palloc_*`, so a groomed replacement object yields an attacker-chosen inode pointer and arbitrary kernel memory read; `root->ifile` itself is also already freed and its address_space is read out of freed memory.\nI:H - `atomic64_dec(&ii->i_root->inodes_count)` writes directly into the freed slab object at a fixed offset, and `nilfs_ifile_delete_inode()` performs `raw_inode->i_flags = 0` plus `mark_buffer_dirty()` through the attacker-reclaimable `->ifile` pointer, giving write primitives suitable for control-flow hijacking as well as corrupting ifile/allocator metadata written back to disk.\nA:H - This is a use-after-free that syzbot detected via KASAN; dereferencing the freed `nilfs_root` and the already-`iput()`ed ifile inode during unmount readily oopses or panics the kernel, and the corruption drives further filesystem failure." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nilfs2/inode.c" ], "versions": [ { "version": "e912a5b66837ee89fb025e67b5efeaa11930c2ce", "lessThan": "f31e18131ee2ce80a4da5c808221d25b1ae9ad6d", "status": "affected", "versionType": "git" }, { "version": "e912a5b66837ee89fb025e67b5efeaa11930c2ce", "lessThan": "2a782ea8ebd712a458466e3103e2881b4f886cb5", "status": "affected", "versionType": "git" }, { "version": "e912a5b66837ee89fb025e67b5efeaa11930c2ce", "lessThan": "116d53f09ff52e6f98e3fe1f85d8898d6ba26c68", "status": "affected", "versionType": "git" }, { "version": "e912a5b66837ee89fb025e67b5efeaa11930c2ce", "lessThan": "6b4205ea97901f822004e6c8d59484ccfda03faa", "status": "affected", "versionType": "git" }, { "version": "e912a5b66837ee89fb025e67b5efeaa11930c2ce", "lessThan": "b8427b8522d9ede53015ba45a9978ba68d1162f5", "status": "affected", "versionType": "git" }, { "version": "e912a5b66837ee89fb025e67b5efeaa11930c2ce", "lessThan": "acc2a40e428f12780004e1e9fce4722d88f909fd", "status": "affected", "versionType": "git" }, { "version": "e912a5b66837ee89fb025e67b5efeaa11930c2ce", "lessThan": "fb8e8d58f116d069e5939e1f786ac84e7fa4533e", "status": "affected", "versionType": "git" }, { "version": "e912a5b66837ee89fb025e67b5efeaa11930c2ce", "lessThan": "9b5a04ac3ad9898c4745cba46ea26de74ba56a8e", "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/nilfs2/inode.c" ], "versions": [ { "version": "2.6.37", "status": "affected" }, { "version": "0", "lessThan": "2.6.37", "status": "unaffected", "versionType": "semver" }, { "version": "4.14.316", "lessThanOrEqual": "4.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.284", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.244", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.181", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.113", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.30", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.3.4", "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": "2.6.37", "versionEndExcluding": "4.14.316" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "4.19.284" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "5.4.244" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "5.10.181" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "5.15.113" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "6.1.30" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "6.3.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "6.4" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/f31e18131ee2ce80a4da5c808221d25b1ae9ad6d" }, { "url": "https://git.kernel.org/stable/c/2a782ea8ebd712a458466e3103e2881b4f886cb5" }, { "url": "https://git.kernel.org/stable/c/116d53f09ff52e6f98e3fe1f85d8898d6ba26c68" }, { "url": "https://git.kernel.org/stable/c/6b4205ea97901f822004e6c8d59484ccfda03faa" }, { "url": "https://git.kernel.org/stable/c/b8427b8522d9ede53015ba45a9978ba68d1162f5" }, { "url": "https://git.kernel.org/stable/c/acc2a40e428f12780004e1e9fce4722d88f909fd" }, { "url": "https://git.kernel.org/stable/c/fb8e8d58f116d069e5939e1f786ac84e7fa4533e" }, { "url": "https://git.kernel.org/stable/c/9b5a04ac3ad9898c4745cba46ea26de74ba56a8e" } ], "title": "nilfs2: fix use-after-free bug of nilfs_root in nilfs_evict_inode()", "x_generator": { "engine": "bippy-1.2.0" } } } }