Hello, On (04/13/17 09:17), Minchan Kim wrote: > The copy_page is optimized memcpy for page-alinged address. > If it is used with non-page aligned address, it can corrupt memory which > means system corruption. With zram, it can happen with > > 1. 64K architecture > 2. partial IO > 3. slub debug > > Partial IO need to allocate a page and zram allocates it via kmalloc. > With slub debug, kmalloc(PAGE_SIZE) doesn't return page-size aligned > address. And finally, copy_page(mem, cmem) corrupts memory. which would be the case for many other copy_page() calls in the kernel. right? if so - should the fix be in copy_page() then? -ss