{"id":"CVE-2026-80810","revision":"de7b52b99d7c4f018db5f7e3aefe4e79","records":[{"revision":"de7b52b99d7c4f018db5f7e3aefe4e79","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-80810","aliases":[],"title":"io_uring/rsrc: fix folio size overflow in io_vec_fill_bvec()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/rsrc: fix folio size overflow in io_vec_fill_bvec()\n\nio_vec_fill_bvec() computes the folio size with a plain int 1:\n\n\tunsigned long folio_size = 1 << imu->folio_shift;\n\nimu->folio_shift is unsigned int and comes from folio_shift() of the\nfolio backing the registered buffer, so it can be 32 or more on a 64 bit\nkernel. Shifting int 1 that far is undefined, and on x86 and arm64 the\ncount is taken modulo 32, so a shift of 34 yields 4 rather than 16G.\nEvery other folio_shift shift in this file already uses 1UL.\n\nThe result is that the segment estimate and the fill loop disagree.\nio_estimate_bvec_size() sizes the bvec array with the real shift:\n\n\tmax_segs += (iov[i].iov_len >> shift) + 2;\n\nso a 1M iovec on a 16G folio is charged 2 segments, while\nio_vec_fill_bvec() then walks the same iovec in folio_size chunks of 4\nbytes and writes res_bvec[bvec_idx] a quarter of a million times, past\nthe end of the array it was given. src_bvec is advanced once per\niteration as well, so imu->bvec is read past its end at the same time.\nvalidate_fixed_range() only checks that the range is inside the\nregistered buffer and does not bound the segment count.\n\nReaching it needs a folio with a shift of at least 32, which means a\ngigantic hugetlb page: 16G on arm64 with 64K pages, where\nCONT_PMD_SHIFT is 34 and hugetlb_add_hstate(CONT_PMD_SHIFT - PAGE_SHIFT)\nregisters that size, and likewise on powerpc. x86_64 tops out at 1G, so\na shift of 30, which still fits in int and is unaffected.\n\nUse 1UL, as the rest of the file does.","state":0,"publishedAt":"2026-09-04T15:13:30.8+00:00","modifiedAt":"2026-10-19T08:44:03.724+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                        \"io_uring/rsrc.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"9ef4cbbcb4ac3786a1a4164507511b76b2a572c5\",\n                            \"lessThan\": \"45c945107e007b1fb73e21cd220277652a45521a\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9ef4cbbcb4ac3786a1a4164507511b76b2a572c5\",\n                            \"lessThan\": \"6b308c37fbeba3aa8c634fb1ed53e2f63a5d5a5c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9ef4cbbcb4ac3786a1a4164507511b76b2a572c5\",\n                            \"lessThan\": \"3267d7c8ba51642117f7bdd1ece02b2540668476\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9ef4cbbcb4ac3786a1a4164507511b76b2a572c5\",\n                            \"lessThan\": \"3f3a6a16bbe8bde76532d9415438f8cdef439e5d\",\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                        \"io_uring/rsrc.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.15\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.15\",\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/45c945107e007b1fb73e21cd220277652a45521a","https://git.kernel.org/stable/c/6b308c37fbeba3aa8c634fb1ed53e2f63a5d5a5c","https://git.kernel.org/stable/c/3267d7c8ba51642117f7bdd1ece02b2540668476","https://git.kernel.org/stable/c/3f3a6a16bbe8bde76532d9415438f8cdef439e5d"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80810","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-80810","identifiers":["CVE-2026-80810"]},"retained":false,"historicalAffected":[]}],"coverage":[]}