{"id":"CVE-2026-89677","summary":"nfsd: fix possible fh_compose of wrong dentry in nfsd4_create_file()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix possible fh_compose of wrong dentry in nfsd4_create_file()\n\ndentry_create() can hypothetically provide a different dentry than the\none passed in.  This could happen, for example, if the exported\nfilesystem is NFS, and the server returned to OPEN a filehandle which\nmatched a directory that was already in the dcache.  Clearly this would\nnot be expected!\n\nIf this were to happen the dentry (child) that was already stored in\nresfhp could be freed and later dereferenced.\n\nWe shouldn't call fh_compose() until we are certain that we have the\nfinal dentry, so this patch moved the fh_compose() call to two places:\none for the case where the target already exists, and one after\ndentry_create() where it was created.","modified":"2026-09-12T11:47:15.943922779Z","published":"2026-09-11T19:46:01.185Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89677.json","cna_assigner":"Linux"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/033e783709ce99662cf81f6abcad746a8da9d35f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3e2c79360c6a89975ec5b5a7d4ef937e4db91a27"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89677.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89677"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"64a989dbd144e0622371396461b11335459692d2"},{"fixed":"033e783709ce99662cf81f6abcad746a8da9d35f"},{"fixed":"3e2c79360c6a89975ec5b5a7d4ef937e4db91a27"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89677.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.0.0"},{"fixed":"7.2.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89677.json"}}],"schema_version":"1.9.0"}