{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-97594", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-24T16:01:01.157Z", "datePublished": "2026-09-25T10:22:10.548Z", "dateUpdated": "2026-10-21T12:53:22.513Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:53:22.513Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nlandlock: Fix use-after-free of the source's parent directory\n\ncurrent_check_refer_path() reads old_dentry->d_parent without holding a\nreference nor a lock on it, and then dereferences it in\ncollect_domain_accesses() and in the audit record.\n\nA reference on a child does not pin its parent: __d_move() reassigns\ndentry->d_parent and drops the reference the child held on its former\nparent. hook_path_rename() is not affected because the rename path\ncalls lock_rename() before the hook, so the source cannot be reparented\nunder it. hook_path_link() has no such protection: filename_linkat()\nholds a reference on the source dentry but neither locks nor references\nits parent, so a concurrent rename(2) can reparent the source while\nsecurity_path_link() runs, and the former parent can then be removed and\nfreed while the hook walks it.\n\nA process can trigger this after entering a Landlock domain that handles\nat least one filesystem access right. The process can then race a\nlinkat(2) loop against rename(2) and rmdir(2):\n\n BUG: KASAN: slab-use-after-free in collect_domain_accesses+0x278/0x290\n Read of size 4 at addr ffff888160bd53f4 by task llrepro2/549\n collect_domain_accesses+0x278/0x290\n current_check_refer_path+0x952/0x1120\n security_path_link+0x1be/0x320\n filename_linkat+0x342/0x6d0\n __x64_sys_linkat+0xfa/0x150\n Freed by task 562:\n kmem_cache_free+0x139/0x4c0\n i_callback+0x4b/0x80\n rcu_core+0x7dc/0x10a0\n\nTake a reference on the dentry selected as the source parent, using\ndget() for the common-mount-root case and dget_parent() otherwise.\nRelease it after the hierarchy walk and synchronous audit logging.\n\n[mic: Clarify the caller, reachability, and reference handling]" } ], "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 trigger is a local linkat(2) syscall: filename_linkat() -> security_path_link() -> hook_path_link() -> current_check_refer_path(), raced against local rename(2)/rmdir(2). No remote protocol supplies any of the input.\nAC:L - The attacker runs every side of the race: a linkat() loop on their own file, plus rename() to reparent the source and rmdir() to free the old parent, all in directories they create (e.g. /tmp). No condition outside the attacker's control is needed; the window can be retried at will.\nPR:L - An ordinary unprivileged user can enter a Landlock domain that handles any FS right (landlock_create_ruleset + landlock_restrict_self after PR_SET_NO_NEW_PRIVS, no capability needed); that makes landlock_get_applicable_subject() non-NULL and reaches the unpinned d_parent read.\nUI:N - The attacker's own syscalls on files and directories they own trigger the bug; no other user or administrator has to do anything.\nS:U - The corruption happens in kernel memory under the same kernel authority; exploiting it is standard local privilege escalation, not a crossing into a separate authority such as a hypervisor.\nC:H - collect_domain_accesses() dereferences the freed old_parent dentry and follows its d_parent/d_inode pointers into the Landlock inode blob via find_rule(). If the attacker reallocates the freed slab, they control pointers that the kernel then follows and reads.\nI:H - collect_domain_accesses() calls dget() and later dput() on the freed dentry. That writes the lockref inside the freed or reallocated object and can run dentry teardown on it, a write primitive that can lead to a double free or control-flow hijack.\nA:H - The KASAN report in the commit shows a slab use-after-free in collect_domain_accesses(). On production kernels the refcount changes on freed memory or the stale pointer walk can oops or panic the kernel." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "security/landlock/fs.c" ], "versions": [ { "version": "b91c3e4ea756b12b7d992529226edce1cfd854d7", "lessThan": "48fc1c74052c956c59d5b16b5e18e0dd36b76aa2", "status": "affected", "versionType": "git" }, { "version": "b91c3e4ea756b12b7d992529226edce1cfd854d7", "lessThan": "4c37992b9668c4f37aae41dd95c369f7b6009915", "status": "affected", "versionType": "git" }, { "version": "b91c3e4ea756b12b7d992529226edce1cfd854d7", "lessThan": "379efd2ce8b26fd35feb13ccc2f671ff105a5052", "status": "affected", "versionType": "git" }, { "version": "b91c3e4ea756b12b7d992529226edce1cfd854d7", "lessThan": "ba29c46ccfe3ebadfb8aa18149186c49f84b14f8", "status": "affected", "versionType": "git" }, { "version": "b91c3e4ea756b12b7d992529226edce1cfd854d7", "lessThan": "2c6dc792538260a8087ac5b22c31b3b8e47c85d6", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "security/landlock/fs.c" ], "versions": [ { "version": "5.19", "status": "affected" }, { "version": "0", "lessThan": "5.19", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.112", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.53", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.7", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "5.19", "versionEndExcluding": "6.6.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.12.112" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.18.53" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "7.2.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/48fc1c74052c956c59d5b16b5e18e0dd36b76aa2" }, { "url": "https://git.kernel.org/stable/c/4c37992b9668c4f37aae41dd95c369f7b6009915" }, { "url": "https://git.kernel.org/stable/c/379efd2ce8b26fd35feb13ccc2f671ff105a5052" }, { "url": "https://git.kernel.org/stable/c/ba29c46ccfe3ebadfb8aa18149186c49f84b14f8" }, { "url": "https://git.kernel.org/stable/c/2c6dc792538260a8087ac5b22c31b3b8e47c85d6" } ], "title": "landlock: Fix use-after-free of the source's parent directory", "x_generator": { "engine": "bippy-1.2.0" } } } }