{"id":"CVE-2026-80778","revision":"6d082cbff5a1453b81331de0d6e61e84","records":[{"revision":"6d082cbff5a1453b81331de0d6e61e84","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-80778","aliases":[],"title":"futex/pi: Reject cross-mm private futex owners","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfutex/pi: Reject cross-mm private futex owners\n\nA private futex key borrows the waiter's mm without taking an mm_users\nreference. Nevertheless, attach_to_pi_owner() currently accepts an owner\nfrom a different address space and copies the private key into the owner's\nPI state.\n\nWhen that owner exits, exit_pi_state_list() uses the saved key to find the\nhash bucket and acquires a reference to the waiter's private hash. If the\nlast user of the waiter's mm exits concurrently, futex_hash_free() frees\nthe hash while the owner still uses its bucket and reference.\n\nPrevent this by validating in attach_to_pi_owner() that, for private\nfutexes, the owner mm and waiter mm are the same. Perform the check with\nthe owner's pi_lock held and after validating owner::futex::state to\nserialize against a concurrent PI-state exit cleanup.\n\n[ tglx: Amended comment ]","state":0,"publishedAt":"2026-09-04T15:12:50.117+00:00","modifiedAt":"2026-10-19T08:43:33.681+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                        \"kernel/futex/pi.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"80367ad01d93ac781b0e1df246edaf006928002f\",\n                            \"lessThan\": \"2b92e5562653b5293529f63b0300837d9dcedbd7\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"80367ad01d93ac781b0e1df246edaf006928002f\",\n                            \"lessThan\": \"f7fb3e07752688842cbe0b85cf0d98c2fbf76b68\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"80367ad01d93ac781b0e1df246edaf006928002f\",\n                            \"lessThan\": \"43b148d796aa338858792d0167cebdc12b8cb4b9\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"80367ad01d93ac781b0e1df246edaf006928002f\",\n                            \"lessThan\": \"59b3732f95dda1fbd2234514d35f4fb6b5bb6d85\",\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                        \"kernel/futex/pi.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.16\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.16\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.47\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.11\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.1\",\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/2b92e5562653b5293529f63b0300837d9dcedbd7","https://git.kernel.org/stable/c/f7fb3e07752688842cbe0b85cf0d98c2fbf76b68","https://git.kernel.org/stable/c/43b148d796aa338858792d0167cebdc12b8cb4b9","https://git.kernel.org/stable/c/59b3732f95dda1fbd2234514d35f4fb6b5bb6d85"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80778","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-80778","identifiers":["CVE-2026-80778"]},"retained":false,"historicalAffected":[]}],"coverage":[]}