{"id":"CVE-2023-53246","summary":"cifs: fix DFS traversal oops without CONFIG_CIFS_DFS_UPCALL","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: fix DFS traversal oops without CONFIG_CIFS_DFS_UPCALL\n\nWhen compiled with CONFIG_CIFS_DFS_UPCALL disabled, cifs_dfs_d_automount\nis NULL. cifs.ko logic for mapping CIFS_FATTR_DFS_REFERRAL attributes to\nS_AUTOMOUNT and corresponding dentry flags is retained regardless of\nCONFIG_CIFS_DFS_UPCALL, leading to a NULL pointer dereference in\nVFS follow_automount() when traversing a DFS referral link:\n  BUG: kernel NULL pointer dereference, address: 0000000000000000\n  ...\n  Call Trace:\n   \u003cTASK\u003e\n   __traverse_mounts+0xb5/0x220\n   ? cifs_revalidate_mapping+0x65/0xc0 [cifs]\n   step_into+0x195/0x610\n   ? lookup_fast+0xe2/0xf0\n   path_lookupat+0x64/0x140\n   filename_lookup+0xc2/0x140\n   ? __create_object+0x299/0x380\n   ? kmem_cache_alloc+0x119/0x220\n   ? user_path_at_empty+0x31/0x50\n   user_path_at_empty+0x31/0x50\n   __x64_sys_chdir+0x2a/0xd0\n   ? exit_to_user_mode_prepare+0xca/0x100\n   do_syscall_64+0x42/0x90\n   entry_SYSCALL_64_after_hwframe+0x72/0xdc\n\nThis fix adds an inline cifs_dfs_d_automount() {return -EREMOTE} handler\nwhen CONFIG_CIFS_DFS_UPCALL is disabled. An alternative would be to\navoid flagging S_AUTOMOUNT, etc. without CONFIG_CIFS_DFS_UPCALL. This\napproach was chosen as it provides more control over the error path.","modified":"2026-04-02T09:43:51.382526Z","published":"2025-09-15T14:46:15.977Z","related":["SUSE-SU-2025:03614-1","SUSE-SU-2025:03615-1","SUSE-SU-2025:03628-1","SUSE-SU-2025:3716-1","SUSE-SU-2025:3761-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53246.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/179a88a8558bbf42991d361595281f3e45d7edfc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/1e144b68208e98fd4602c842a7149ba5f41d87fb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/26a32a212bc540f4773cd6af8cf73e967d72569c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b64305185b76f1d5145ce594ff48f3f0e70695bd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b7d854c33ab48e55fc233699bbefe39ec9bb5c05"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53246.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-53246"},{"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":"25e195aa1e607f129ab912d29fcfc79239703307"},{"fixed":"26a32a212bc540f4773cd6af8cf73e967d72569c"},{"fixed":"b64305185b76f1d5145ce594ff48f3f0e70695bd"},{"fixed":"b7d854c33ab48e55fc233699bbefe39ec9bb5c05"},{"fixed":"1e144b68208e98fd4602c842a7149ba5f41d87fb"},{"fixed":"179a88a8558bbf42991d361595281f3e45d7edfc"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-53246.json"}}],"schema_version":"1.7.5"}