{"id":"CVE-2026-89766","revision":"f17db47b19d94671981d2bdceb538b6a","records":[{"revision":"f17db47b19d94671981d2bdceb538b6a","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89766","aliases":[],"title":"pidfd: hold exec_update_lock around namespace ioctl","description":"In the Linux kernel, the following vulnerability has been resolved:\n\npidfd: hold exec_update_lock around namespace ioctl\n\nThe PIDFD_GET_*_NAMESPACE ioctls in pidfd_ioctl() perform a filesystem\ncredentials ptrace access check before handing out a namespace file\ndescriptor.  The accompanying comment states that the code \"mirrors nsfs\nbehavior\", but, unlike the corresponding procfs paths, it does so without\nholding the target task's exec_update_lock.\n\nproc_ns_get_link() and proc_ns_readlink() both take exec_update_lock for\nreading around the ptrace check and the namespace lookup, so that the\ncredentials used for the access decision match those of the task when its\nnamespace is read.  Without it, a caller can pass the check against the\ntarget's old credentials and then read the namespace after the target has\nexecve()'d a setuid binary and committed new credentials -- accessing\nnamespace information it should have been denied.\n\nHold exec_update_lock for reading around the ptrace check and the\nnamespace lookup so that pidfd truly mirrors nsfs behavior, as the comment\nalready claims.  open_namespace() itself runs outside the lock: once a\nnamespace reference is obtained it carries its own refcount and is opened\nwith the caller's own credentials, so a concurrent execve() on the target\ncan no longer affect the outcome.","state":0,"publishedAt":"2026-09-11T19:47:06.597+00:00","modifiedAt":"2026-10-19T08:52:19.816+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/pidfs.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5b08bd408534bfb3a7cf5778da5b27d4e4fffe12\",\n                            \"lessThan\": \"bac2f1913a216677c2c220d7bb352dd0330065ca\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5b08bd408534bfb3a7cf5778da5b27d4e4fffe12\",\n                            \"lessThan\": \"cf24ce48d60225fdbee68ed2058763a1fd172ff3\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5b08bd408534bfb3a7cf5778da5b27d4e4fffe12\",\n                            \"lessThan\": \"e89318aa8629969e86548b05e7c19283af3f0efb\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5b08bd408534bfb3a7cf5778da5b27d4e4fffe12\",\n                            \"lessThan\": \"9688a46802939da28f00cb40e8129615d5d4af39\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/pidfs.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.11\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.11\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.112\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.51\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.4\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/bac2f1913a216677c2c220d7bb352dd0330065ca","https://git.kernel.org/stable/c/cf24ce48d60225fdbee68ed2058763a1fd172ff3","https://git.kernel.org/stable/c/e89318aa8629969e86548b05e7c19283af3f0efb","https://git.kernel.org/stable/c/9688a46802939da28f00cb40e8129615d5d4af39"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89766","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89766","identifiers":["CVE-2026-89766"]},"retained":false,"historicalAffected":[]}],"coverage":[]}