Description
In the Linux kernel, the following vulnerability has been resolved:

ksmbd: Do not skip lock checks for single-byte ranges

check_lock_range() uses inclusive ranges. Its callers pass the end
offset as start + length - 1, so start == end represents a valid
single-byte range rather than an empty range.

The start == end shortcut therefore skips mandatory byte-range lock
checks for one-byte reads, writes, copychunk operations and one-byte
truncate ranges. A conflicting lock covering that byte is not checked
and the operation is allowed to proceed.

Remove the shortcut. The truncate size == inode->i_size case is already
handled by only calling check_lock_range() when the new size differs
from the current file size.
Published: 2026-09-17
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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History

Thu, 17 Sep 2026 16:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: ksmbd: Do not skip lock checks for single-byte ranges check_lock_range() uses inclusive ranges. Its callers pass the end offset as start + length - 1, so start == end represents a valid single-byte range rather than an empty range. The start == end shortcut therefore skips mandatory byte-range lock checks for one-byte reads, writes, copychunk operations and one-byte truncate ranges. A conflicting lock covering that byte is not checked and the operation is allowed to proceed. Remove the shortcut. The truncate size == inode->i_size case is already handled by only calling check_lock_range() when the new size differs from the current file size.
Title ksmbd: Do not skip lock checks for single-byte ranges
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-17T16:07:02.433Z

Reserved: 2026-09-11T19:38:34.791Z

Link: CVE-2026-90176

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-17T17:17:11.387

Modified: 2026-09-17T17:17:11.387

Link: CVE-2026-90176

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.