{"api_version":"1","generated_at":"2026-09-13T12:09:49+00:00","cve":"CVE-2026-80810","urls":{"html":"https://cve.report/CVE-2026-80810","api":"https://cve.report/api/cve/CVE-2026-80810.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-80810","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-80810"},"summary":{"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":"PUBLISHED","assigner":"Linux","published_at":"2026-09-04 16:18:08","updated_at":"2026-09-04 16:18:08"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/6b308c37fbeba3aa8c634fb1ed53e2f63a5d5a5c","name":"https://git.kernel.org/stable/c/6b308c37fbeba3aa8c634fb1ed53e2f63a5d5a5c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/45c945107e007b1fb73e21cd220277652a45521a","name":"https://git.kernel.org/stable/c/45c945107e007b1fb73e21cd220277652a45521a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/3267d7c8ba51642117f7bdd1ece02b2540668476","name":"https://git.kernel.org/stable/c/3267d7c8ba51642117f7bdd1ece02b2540668476","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/3f3a6a16bbe8bde76532d9415438f8cdef439e5d","name":"https://git.kernel.org/stable/c/3f3a6a16bbe8bde76532d9415438f8cdef439e5d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80810","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80810","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 9ef4cbbcb4ac3786a1a4164507511b76b2a572c5 45c945107e007b1fb73e21cd220277652a45521a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 9ef4cbbcb4ac3786a1a4164507511b76b2a572c5 6b308c37fbeba3aa8c634fb1ed53e2f63a5d5a5c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 9ef4cbbcb4ac3786a1a4164507511b76b2a572c5 3267d7c8ba51642117f7bdd1ece02b2540668476 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 9ef4cbbcb4ac3786a1a4164507511b76b2a572c5 3f3a6a16bbe8bde76532d9415438f8cdef439e5d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.15","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.15 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.47 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.11 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.1 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"80810","cve":"CVE-2026-80810","epss":"0.001680000","percentile":"0.063030000","score_date":"2026-09-07","updated_at":"2026-09-08 00:05:27"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["io_uring/rsrc.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"45c945107e007b1fb73e21cd220277652a45521a","status":"affected","version":"9ef4cbbcb4ac3786a1a4164507511b76b2a572c5","versionType":"git"},{"lessThan":"6b308c37fbeba3aa8c634fb1ed53e2f63a5d5a5c","status":"affected","version":"9ef4cbbcb4ac3786a1a4164507511b76b2a572c5","versionType":"git"},{"lessThan":"3267d7c8ba51642117f7bdd1ece02b2540668476","status":"affected","version":"9ef4cbbcb4ac3786a1a4164507511b76b2a572c5","versionType":"git"},{"lessThan":"3f3a6a16bbe8bde76532d9415438f8cdef439e5d","status":"affected","version":"9ef4cbbcb4ac3786a1a4164507511b76b2a572c5","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["io_uring/rsrc.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.15"},{"lessThan":"6.15","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.47","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.11","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.1","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.47","versionStartIncluding":"6.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.11","versionStartIncluding":"6.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.1","versionStartIncluding":"6.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"6.15","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"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."}],"providerMetadata":{"dateUpdated":"2026-09-04T15:13:30.800Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/45c945107e007b1fb73e21cd220277652a45521a"},{"url":"https://git.kernel.org/stable/c/6b308c37fbeba3aa8c634fb1ed53e2f63a5d5a5c"},{"url":"https://git.kernel.org/stable/c/3267d7c8ba51642117f7bdd1ece02b2540668476"},{"url":"https://git.kernel.org/stable/c/3f3a6a16bbe8bde76532d9415438f8cdef439e5d"}],"title":"io_uring/rsrc: fix folio size overflow in io_vec_fill_bvec()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-80810","datePublished":"2026-09-04T15:13:30.800Z","dateReserved":"2026-08-26T14:34:25.794Z","dateUpdated":"2026-09-04T15:13:30.800Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-04 16:18:08","lastModifiedDate":"2026-09-04 16:18:08","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"80810","Ordinal":"1","Title":"io_uring/rsrc: fix folio size overflow in io_vec_fill_bvec()","CVE":"CVE-2026-80810","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"80810","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"io_uring/rsrc: fix folio size overflow in io_vec_fill_bvec()"}]}}}