CVE-2026-90176ksmbd: Do not skip lock checks for single-byte ranges
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 8.1 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Received
- Record last updated
- Sep 18, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 52fcbb92e0d3acfd1448b2a43b6595d540da5295 before a89cc145832e81c32199d4ca2e1ea8bd51ed601d; from da29cd197246c85c0473259f1cad897d9d28faea before 993e0158331d37c04da18efe551b5e1e35fb3078; from a6f4cfa3783804336491e0edcb250c25f9b59d33 before f751d6e39d4c937c45f8fedc66699aa7d2d52288; 571204e4758a528fbd67330bd4b0dfbdafb33dd8 builds before 84c2d8e807ac489f5c91769293fb15dfdae8bae8; from 5d510ac31626ed157d2182149559430350cf2104 before 07a9e289ff7edcc004f58952405f8a65c4e37512; from 5d510ac31626ed157d2182149559430350cf2104 before d40c24634fe077a0dc91fd11fccf44ce12b454d5; from 6.1.160 before 6.1.188; from 6.6.120 before 6.6.157; and 2 more ranges | CNA record |
References
- https://git.kernel.org/stable/c/a89cc145832e81c32199d4ca2e1ea8bd51ed601d
- https://git.kernel.org/stable/c/993e0158331d37c04da18efe551b5e1e35fb3078
- https://git.kernel.org/stable/c/f751d6e39d4c937c45f8fedc66699aa7d2d52288
- https://git.kernel.org/stable/c/84c2d8e807ac489f5c91769293fb15dfdae8bae8
- https://git.kernel.org/stable/c/07a9e289ff7edcc004f58952405f8a65c4e37512
- https://git.kernel.org/stable/c/d40c24634fe077a0dc91fd11fccf44ce12b454d5
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.