CVE-2026-64053

block: don't overwrite bip_vcnt in bio_integrity_copy_user()

HIGH
7.8
CVSS Score
Published: July 19, 2026 at 03:39 PM UTC
Updated: October 19, 2026 at 09:17 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.8
Exploit prediction
EPSS 0.1%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: block: don't overwrite bip_vcnt in bio_integrity_copy_user() bio_integrity_add_page() already sets bip_vcnt to 1 for the bounce segment. Overwriting it with nr_vecs breaks bip_vcnt <= bip_max_vcnt on WRITE (bip_max_vcnt is 1), so the gap-merge checks in block/blk.h read past the bip_vec[] flex array. On READ the read is in bounds but lands on a saved user bvec instead of the bounce. The line was added for split propagation, but bio_integrity_clone() doesn't copy bip_vcnt and BIP_CLONE_FLAGS excludes BIP_COPY_USER.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.11 ≤ v < 6.12.926.13 ≤ v < 6.18.346.19 ≤ v < 7.0.113991657ae7074c3c497bf095093178bed37ea1b47.17.1 rc17.1 rc27.1 rc3
Vendor states this is fixed in 066be1439593a381b1a29663becfcfe0c92363e7 (fixed)
Vendor states this is fixed in 0d48654af4d1390c888389206cc13b51b82c30e6 (fixed)
Vendor states this is fixed in 637ad3a56a3b889527d1dacea6fea2a8bd648140 (fixed)
Vendor states this is fixed in d18160c9525c63c203656fefd847e94b538cd4a4 (fixed)
Vendor states this is fixed in 6.11 (unaffected)
Vendor states this is fixed in 6.12.92 (unaffected)
Vendor states this is fixed in 6.18.34 (unaffected)
Vendor states this is fixed in 7.0.11 (unaffected)
Vendor states this is fixed in 7.1 (unaffected)

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.8HIGHLinux
Vector?

Quick Info

StatusMODIFIED
CWE
NVD-CWE-noinfoCWE-125

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