Re: [PATCH 24/25] xor: pass the entire operation to the low-level ops

Eric Biggers
2026-02-28T06:58:18Z

On Thu, Feb 26, 2026 at 07:10:36AM -0800, Christoph Hellwig wrote:
> +#define __DO_XOR_BLOCKS(_name, _handle1, _handle2, _handle3, _handle4) \
> +void \
> +xor_gen_##_name(void *dest, void **srcs, unsigned int src_cnt, \
> + unsigned int bytes) \
> +{ \
> + unsigned int src_off = 0; \
> + \
> + while (src_cnt > 0) { \
> + unsigned int this_cnt = min(src_cnt, 4); \
> + unsigned long *p1 = (unsigned long *)srcs[src_off]; \
> + unsigned long *p2 = (unsigned long *)srcs[src_off + 1]; \
> + unsigned long *p3 = (unsigned long *)srcs[src_off + 2]; \
> + unsigned long *p4 = (unsigned long *)srcs[src_off + 3]; \

This reads out of bounds if src_cnt isn't a multiple of 4.

- Eric