Medium · published June 24, 2026
In the Linux kernel, the following vulnerability has been resolved:
erofs: unify lcn as u64 for 32-bit platforms
As sashiko reported [1], `lcn` was typed as `unsigned long` (or
`unsigned int` sometimes), which is only 32 bits wide on 32-bit
platforms, which causes `(lcn << lclusterbits)` to be truncated
at 4 GiB.
In order to consolidate the logic, just use `u64` consistently
around the codebase.
[1] https://sashiko.dev/r/20260420034612.1899973-1-hsiangkao%40linux.alibaba.com
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 5.3, < 6.12.91 | 6.12.91 |
| linux/linux_kernel | ≥ 6.13, < 6.18.33 | 6.18.33 |
| linux/linux_kernel | ≥ 6.19, < 7.0.10 | 7.0.10 |