{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-54050", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-12-24T12:21:05.090Z", "datePublished": "2025-12-24T12:23:00.366Z", "dateUpdated": "2026-08-05T09:16:47.787Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T09:16:47.787Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nubifs: Fix memleak when insert_old_idx() failed\n\nFollowing process will cause a memleak for copied up znode:\n\ndirty_cow_znode\n zn = copy_znode(c, znode);\n err = insert_old_idx(c, zbr->lnum, zbr->offs);\n if (unlikely(err))\n return ERR_PTR(err); // No one refers to zn.\n\nFetch a reproducer in [Link].\n\nFunction copy_znode() is split into 2 parts: resource allocation\nand znode replacement, insert_old_idx() is split in similar way,\nso resource cleanup could be done in error handling path without\ncorrupting metadata(mem & disk).\nIt's okay that old index inserting is put behind of add_idx_dirt(),\nold index is used in layout_leb_in_gaps(), so the two processes do\nnot depend on each other." } ], "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 vulnerable path is reached only through local filesystem syscalls (write/create/unlink/rename/truncate) on a mounted UBIFS volume via ubifs_jnl_* → ubifs_tnc_add/remove → lookup_level0_dirty → dirty_cow_znode. No network protocol handler parses remote data into this code.\nAC:L - Both preconditions are attacker-driven: the COW branch is entered by forcing a commit with fsync/sync while doing metadata work, and the GFP_NOFS allocation failure is produced by deliberately induced memory pressure, which is readily achievable by an unprivileged process on the memory-constrained embedded systems where UBIFS is deployed and which simultaneously activates the shrinker path that turns the corruption into a UAF.\nPR:L - Only an unprivileged local user with write access to any directory on the UBIFS mount is needed; there is no capability, namespace, or admin check anywhere between the syscall entry and dirty_cow_znode.\nUI:N - The attacker triggers everything with their own file operations on an already-mounted filesystem; no victim action, no mount by another user, and no special file is required.\nS:U - The corruption is confined to the kernel's own TNC structures and the mounted filesystem; there is no crossing into another security authority such as a hypervisor or IOMMU domain.\nC:H - The dangling zbranch[].znode left after shrink_tnc() frees a child through the orphaned parent yields a use-after-free read of a generic kmalloc slab object, letting the attacker read reclaimed kernel memory through TNC descent and, with a sprayed replacement znode, escalate to arbitrary kernel reads.\nI:H - The same use-after-free gives write access to the freed/reallocated znode (flag setting, key_copy, parent re-pointing), a classic control-flow-hijack primitive, and the truncated commit list plus mis-set cparent additionally corrupt the on-disk index — the commit message itself cites \"corrupting metadata(mem & disk)\".\nA:H - Beyond the znode memory leak, the orphaned root case NULL-derefs in ubifs_tnc_levelorder_next() and runs off the end of ubifs_destroy_tnc_subtree() (oops at shrink or unmount), and the dirty_zn_cnt/parent assertions in get_znodes_to_commit() force the filesystem read-only or BUG() depending on assert_action." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ubifs/tnc.c" ], "versions": [ { "version": "1e51764a3c2ac05a23a22b2a95ddee4d9bffb16d", "lessThan": "cc29c7216d7f057eb0613b97dc38c7e1962a88d2", "status": "affected", "versionType": "git" }, { "version": "1e51764a3c2ac05a23a22b2a95ddee4d9bffb16d", "lessThan": "6f2eee5457bc48b0426dedfd78cdbdea241a6edb", "status": "affected", "versionType": "git" }, { "version": "1e51764a3c2ac05a23a22b2a95ddee4d9bffb16d", "lessThan": "66e9f2fb3e753f820bec2a98e8c6387029988320", "status": "affected", "versionType": "git" }, { "version": "1e51764a3c2ac05a23a22b2a95ddee4d9bffb16d", "lessThan": "3ae75f82c33fa1b4ca2006b55c84f4ef4a428d4d", "status": "affected", "versionType": "git" }, { "version": "1e51764a3c2ac05a23a22b2a95ddee4d9bffb16d", "lessThan": "ef9aac603659e9ffe7d69ae16e3f0fc0991a965b", "status": "affected", "versionType": "git" }, { "version": "1e51764a3c2ac05a23a22b2a95ddee4d9bffb16d", "lessThan": "79079cebbeed624b9d01cfcf1e3254ae1a1f6e14", "status": "affected", "versionType": "git" }, { "version": "1e51764a3c2ac05a23a22b2a95ddee4d9bffb16d", "lessThan": "a6da0ab9847779e05a7416c7a98148b549de69ef", "status": "affected", "versionType": "git" }, { "version": "1e51764a3c2ac05a23a22b2a95ddee4d9bffb16d", "lessThan": "b5fda08ef213352ac2df7447611eb4d383cce929", "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/ubifs/tnc.c" ], "versions": [ { "version": "2.6.27", "status": "affected" }, { "version": "0", "lessThan": "2.6.27", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.283", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.243", "lessThanOrEqual": "5.4.*", "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": "2.6.27", "versionEndExcluding": "4.19.283" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "5.4.243" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "5.10.180" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "5.15.111" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "6.1.28" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "6.2.15" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "6.3.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "6.4" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/cc29c7216d7f057eb0613b97dc38c7e1962a88d2" }, { "url": "https://git.kernel.org/stable/c/6f2eee5457bc48b0426dedfd78cdbdea241a6edb" }, { "url": "https://git.kernel.org/stable/c/66e9f2fb3e753f820bec2a98e8c6387029988320" }, { "url": "https://git.kernel.org/stable/c/3ae75f82c33fa1b4ca2006b55c84f4ef4a428d4d" }, { "url": "https://git.kernel.org/stable/c/ef9aac603659e9ffe7d69ae16e3f0fc0991a965b" }, { "url": "https://git.kernel.org/stable/c/79079cebbeed624b9d01cfcf1e3254ae1a1f6e14" }, { "url": "https://git.kernel.org/stable/c/a6da0ab9847779e05a7416c7a98148b549de69ef" }, { "url": "https://git.kernel.org/stable/c/b5fda08ef213352ac2df7447611eb4d383cce929" } ], "title": "ubifs: Fix memleak when insert_old_idx() failed", "x_generator": { "engine": "bippy-1.2.0" } } } }