[PATCH] erofs: fix offset truncation when shifting pgoff on 32-bit platforms

[Chao Yu]

On 4/20/2026 11:46 AM, Gao Xiang wrote:
> On 32-bit platforms, pgoff_t is 32 bits wide, so left-shifting
> large arbitrary pgoff_t values by PAGE_SHIFT performs 32-bit arithmetic
> and silently truncates the result for pages beyond the 4 GiB boundary.
> 
> Cast the page index to loff_t before shifting to produce a correct
> 64-bit byte offset.
> 
> Fixes: 386292919c25 ("erofs: introduce readmore decompression strategy")
> Fixes: 307210c262a2 ("erofs: verify metadata accesses for file-backed mounts")
> Signed-off-by: Gao Xiang <hsiangkao at linux.alibaba.com>

Reviewed-by: Chao Yu <chao at kernel.org>

Thanks,