{"id":"CVE-2026-89600","revision":"c7b13a71feb542dd8454f3dfea62ad75","records":[{"revision":"c7b13a71feb542dd8454f3dfea62ad75","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89600","aliases":[],"title":"fanotify: fix use-after-free of file range info","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfanotify: fix use-after-free of file range info\n\nfsnotify_pre_content() builds its file_range on the triggering task's\nstack. fanotify_alloc_perm_event() saves a pointer to range.pos in the\nheap-allocated permission event so copy_range_info_to_user() can report\nthe offset later.\n\nThe event reader can set the event state to FAN_EVENT_REPORTED and then\nsleep while preparing the file descriptor. If a signal interrupts the\ntriggering task at that point, fanotify_get_response() changes the state\nto FAN_EVENT_CANCELED and returns. This unwinds the file_range stack\nframe while the reader still owns the event. The reader then dereferences\npevent->ppos and copies the stale stack value to userspace.\n\nKASAN reported:\n\n  BUG: KASAN: use-after-free in fanotify_read+0x293e/0x2970\n  Read of size 8 at addr ffff88811434fc50 by task fanotify_inotif/95\n  Call Trace:\n   fanotify_read+0x293e/0x2970\n   vfs_read+0x177/0xa20\n   ksys_read+0xf7/0x1c0\n   do_syscall_64+0xf9/0x540\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nStore the range position directly in the permission event and use\nFANOTIFY_NO_RANGE when range information is unavailable. The event remains\nalive until the reader finishes, so the reported offset no longer depends\non the triggering task's stack.","state":0,"publishedAt":"2026-09-11T19:45:03.45+00:00","modifiedAt":"2026-10-19T08:49:32.566+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/notify/fanotify/fanotify.c\",\n                        \"fs/notify/fanotify/fanotify.h\",\n                        \"fs/notify/fanotify/fanotify_user.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"870499bc1d4dc04cba1f63dd5e7bc02b983e2458\",\n                            \"lessThan\": \"66aa9a9e6481bfa512ee5b6380eaaec455a954d2\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"870499bc1d4dc04cba1f63dd5e7bc02b983e2458\",\n                            \"lessThan\": \"b8f73b163b646bc56d4dce9c697a578e333f4894\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"870499bc1d4dc04cba1f63dd5e7bc02b983e2458\",\n                            \"lessThan\": \"d7f1cf5be33ef0175a4e8ed8687aeb98fb00a851\",\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/notify/fanotify/fanotify.c\",\n                        \"fs/notify/fanotify/fanotify.h\",\n                        \"fs/notify/fanotify/fanotify_user.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.14\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.14\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.50\",\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":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/66aa9a9e6481bfa512ee5b6380eaaec455a954d2","https://git.kernel.org/stable/c/b8f73b163b646bc56d4dce9c697a578e333f4894","https://git.kernel.org/stable/c/d7f1cf5be33ef0175a4e8ed8687aeb98fb00a851"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89600","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89600","identifiers":["CVE-2026-89600"]},"retained":false,"historicalAffected":[]}],"coverage":[]}