{"id":"CVE-2023-52909","summary":"nfsd: fix handling of cached open files in nfsd4_open codepath","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix handling of cached open files in nfsd4_open codepath\n\nCommit fb70bf124b05 (\"NFSD: Instantiate a struct file when creating a\nregular NFSv4 file\") added the ability to cache an open fd over a\ncompound. There are a couple of problems with the way this currently\nworks:\n\nIt's racy, as a newly-created nfsd_file can end up with its PENDING bit\ncleared while the nf is hashed, and the nf_file pointer is still zeroed\nout. Other tasks can find it in this state and they expect to see a\nvalid nf_file, and can oops if nf_file is NULL.\n\nAlso, there is no guarantee that we'll end up creating a new nfsd_file\nif one is already in the hash. If an extant entry is in the hash with a\nvalid nf_file, nfs4_get_vfs_file will clobber its nf_file pointer with\nthe value of op_file and the old nf_file will leak.\n\nFix both issues by making a new nfsd_file_acquirei_opened variant that\ntakes an optional file pointer. If one is present when this is called,\nwe'll take a new reference to it instead of trying to open the file. If\nthe nfsd_file already has a valid nf_file, we'll just ignore the\noptional file and pass the nfsd_file back as-is.\n\nAlso rework the tracepoints a bit to allow for an \"opened\" variant and\ndon't try to avoid counting acquisitions in the case where we already\nhave a cached open file.","modified":"2026-04-02T09:26:49.646233Z","published":"2024-08-21T06:10:50.303Z","related":["SUSE-SU-2024:3190-1","SUSE-SU-2024:3209-1","SUSE-SU-2024:3483-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/52xxx/CVE-2023-52909.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0b3a551fa58b4da941efeb209b3770868e2eddd7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/0b778361998d6c6356b8d2fc7ddf025fb3224654"},{"type":"WEB","url":"https://git.kernel.org/stable/c/45c08a752982116f3287afcd1bd9c50f4fab0c28"},{"type":"WEB","url":"https://git.kernel.org/stable/c/973acfdfe90c8a4e58ade97ff0653a498531ff2e"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/52xxx/CVE-2023-52909.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-52909"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"c20097329d2c196b818c4666c7820c1378d69d61"},{"fixed":"45c08a752982116f3287afcd1bd9c50f4fab0c28"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"106331a12b0fa5afa6995b1f9ebb03ddcaac6915"},{"fixed":"0b778361998d6c6356b8d2fc7ddf025fb3224654"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"fb70bf124b051d4ded4ce57511dfec6d3ebf2b43"},{"fixed":"973acfdfe90c8a4e58ade97ff0653a498531ff2e"},{"fixed":"0b3a551fa58b4da941efeb209b3770868e2eddd7"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-52909.json"}}],"schema_version":"1.7.5"}