{"id":"CVE-2026-80946","revision":"19ce87faa838423fa9f6f0e83139a2e6","records":[{"revision":"19ce87faa838423fa9f6f0e83139a2e6","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-80946","aliases":[],"title":"fuse: copy request headers via a stack buffer for io-uring","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: copy request headers via a stack buffer for io-uring\n\nThe fuse-io-uring transport copies req->in.h out to the ring in\nfuse_uring_copy_to_ring() and req->out.h back in fuse_uring_commit().\nBoth headers live inside the fuse_request slab object, whose cache\n(fuse_req_cachep) is created without a usercopy whitelist, so copying\nthem directly to/from userspace trips CONFIG_HARDENED_USERCOPY and\npanics:\n\n  usercopy: Kernel memory exposure attempt detected from SLUB object\n  'fuse_request' (offset 56, size 40)!\n  kernel BUG at mm/usercopy.c:102!\n  Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI\n  RIP: 0010:usercopy_abort (mm/usercopy.c:90)\n  Call Trace:\n   __check_heap_object (mm/slub.c:8268)\n   __check_object_size (mm/usercopy.c:197 mm/usercopy.c:258 mm/usercopy.c:223)\n   copy_header_to_ring (fs/fuse/dev_uring.c:618)\n   fuse_uring_prepare_send (fs/fuse/dev_uring.c:776 fs/fuse/dev_uring.c:785)\n   fuse_uring_send_in_task (fs/fuse/dev_uring.c:1306)\n   tctx_task_work_run (io_uring/tw.c:96)\n   task_work_run (kernel/task_work.c:233)\n   io_run_task_work (io_uring/tw.h:84)\n   io_cqring_wait (io_uring/wait.c:278)\n   __do_sys_io_uring_enter (io_uring/io_uring.c:2685)\n   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n\nBounce both headers through an on-stack copy so the usercopy touches\nstack memory, not the slab object.","state":0,"publishedAt":"2026-09-11T19:42:17.576+00:00","modifiedAt":"2026-10-19T08:45:30.291+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/fuse/dev_uring.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"c090c8abae4b6b77a1bee116aa6c385456ebef96\",\n                            \"lessThan\": \"194d0fb0ea4720535ff3168c9d04c7632cec7071\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c090c8abae4b6b77a1bee116aa6c385456ebef96\",\n                            \"lessThan\": \"a47a416ff68d706dc3327ab583f86b9ee757358b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c090c8abae4b6b77a1bee116aa6c385456ebef96\",\n                            \"lessThan\": \"fd10f40af314f07b6d6e028b1ca25c8b49903aab\",\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/fuse/dev_uring.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\": \"6.18.51\",\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/194d0fb0ea4720535ff3168c9d04c7632cec7071","https://git.kernel.org/stable/c/a47a416ff68d706dc3327ab583f86b9ee757358b","https://git.kernel.org/stable/c/fd10f40af314f07b6d6e028b1ca25c8b49903aab"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80946","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-80946","identifiers":["CVE-2026-80946"]},"retained":false,"historicalAffected":[]}],"coverage":[]}