{"id":"CVE-2026-64053","title":"block: don't overwrite bip_vcnt in bio_integrity_copy_user()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nblock: don't overwrite bip_vcnt in bio_integrity_copy_user()\n\nbio_integrity_add_page() already sets bip_vcnt to 1 for the bounce\nsegment. Overwriting it with nr_vecs br…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 3991657ae7074c3c497bf095093178bed37ea1b4 < d18160c9525c63c203656fefd847e94b538cd4a4","Linux >= 3991657ae7074c3c497bf095093178bed37ea1b4 < 0d48654af4d1390c888389206cc13b51b82c30e6","Linux >= 3991657ae7074c3c497bf095093178bed37ea1b4 < 066be1439593a381b1a29663becfcfe0c92363e7","Linux >= 3991657ae7074c3c497bf095093178bed37ea1b4 < 637ad3a56a3b889527d1dacea6fea2a8bd648140","Linux 6.11"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T15:36:00.465098Z"},"published":"2026-07-19","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:42:21.153Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64053","references":[{"url":"https://git.kernel.org/stable/c/d18160c9525c63c203656fefd847e94b538cd4a4"},{"url":"https://git.kernel.org/stable/c/0d48654af4d1390c888389206cc13b51b82c30e6"},{"url":"https://git.kernel.org/stable/c/066be1439593a381b1a29663becfcfe0c92363e7"},{"url":"https://git.kernel.org/stable/c/637ad3a56a3b889527d1dacea6fea2a8bd648140"}],"tags":["cve.org"],"epss":0.00129,"epssPercentile":0.02227,"ingestedAt":"2026-10-16T17:24:46.803Z","slug":"CVE-2026-64053","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nblock: don't overwrite bip_vcnt in bio_integrity_copy_user()\n\nbio_integrity_add_page() already sets bip_vcnt to 1 for the bounce\nsegment. Overwriting it with nr_vecs breaks bip_vcnt <= bip_max_vcnt\non WRITE (bip_max_vcnt is 1), so the gap-merge checks in block/blk.h\nread past the bip_vec[] flex array. On READ the read is in bounds\nbut lands on a saved user bvec instead of the bounce.\n\nThe line was added for split propagation, but bio_integrity_clone()\ndoesn't copy bip_vcnt and BIP_CLONE_FLAGS excludes BIP_COPY_USER.\n\n## Affected\n\n- `Linux >= 3991657ae7074c3c497bf095093178bed37ea1b4 < d18160c9525c63c203656fefd847e94b538cd4a4`\n- `Linux >= 3991657ae7074c3c497bf095093178bed37ea1b4 < 0d48654af4d1390c888389206cc13b51b82c30e6`\n- `Linux >= 3991657ae7074c3c497bf095093178bed37ea1b4 < 066be1439593a381b1a29663becfcfe0c92363e7`\n- `Linux >= 3991657ae7074c3c497bf095093178bed37ea1b4 < 637ad3a56a3b889527d1dacea6fea2a8bd648140`\n- `Linux 6.11`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}