{"id":"CVE-2026-97594","published":"2026-09-25T11:17:10.653","lastModified":"2026-09-25T15:18:00.670","description":"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]","cvssScore":7.8,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/2c6dc792538260a8087ac5b22c31b3b8e47c85d6","tags":[]},{"url":"https://git.kernel.org/stable/c/379efd2ce8b26fd35feb13ccc2f671ff105a5052","tags":[]},{"url":"https://git.kernel.org/stable/c/ba29c46ccfe3ebadfb8aa18149186c49f84b14f8","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}