CVE-2026-90176
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.
How to fix
- Linux Linuxa89cc145832e81c32199d4ca2e1ea8bd51ed601d, 993e0158331d37c04da18efe551b5e1e35fb3078, f751d6e39d4c937c45f8fedc66699aa7d2d52288, 84c2d8e807ac489f5c91769293fb15dfdae8bae8, 07a9e289ff7edcc004f58952405f8a65c4e37512, d40c24634fe077a0dc91fd11fccf44ce12b454d5, 6.1.188, 6.6.157, 6.12.110, 6.18.52 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Linux Linux | 52fcbb92e0d3acfd1448b2a43b6595d540da5295 ≤ v < a89cc145832e81c32199d4ca2e1ea8bd51ed601d, da29cd197246c85c0473259f1cad897d9d28faea ≤ v < 993e0158331d37c04da18efe551b5e1e35fb3078, a6f4cfa3783804336491e0edcb250c25f9b59d33 ≤ v < f751d6e39d4c937c45f8fedc66699aa7d2d52288, 571204e4758a528fbd67330bd4b0dfbdafb33dd8 ≤ v < 84c2d8e807ac489f5c91769293fb15dfdae8bae8, 5d510ac31626ed157d2182149559430350cf2104 ≤ v < 07a9e289ff7edcc004f58952405f8a65c4e37512, 5d510ac31626ed157d2182149559430350cf2104 ≤ v < d40c24634fe077a0dc91fd11fccf44ce12b454d5, 6.1.160 ≤ v < 6.1.188, 6.6.120 ≤ v < 6.6.157, 6.12.64 ≤ v < 6.12.110, 6.18.3 ≤ v < 6.18.52, 6.19 | a89cc145832e81c32199d4ca2e1ea8bd51ed601d, 993e0158331d37c04da18efe551b5e1e35fb3078, f751d6e39d4c937c45f8fedc66699aa7d2d52288, 84c2d8e807ac489f5c91769293fb15dfdae8bae8, 07a9e289ff7edcc004f58952405f8a65c4e37512, d40c24634fe077a0dc91fd11fccf44ce12b454d5, 6.1.188, 6.6.157, 6.12.110, 6.18.52 |
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