Bug 2502498 (CVE-2026-64053) - CVE-2026-64053 kernel: block: don't overwrite bip_vcnt in bio_integrity_copy_user()
Summary: CVE-2026-64053 kernel: block: don't overwrite bip_vcnt in bio_integrity_copy_...
Keywords:
Status: NEW
Alias: CVE-2026-64053
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-07-19 17:02 UTC by OSIDB Bzimport
Modified: 2026-07-21 06:47 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
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Description OSIDB Bzimport 2026-07-19 17:02:40 UTC
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.


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