On Mon, 2015-10-26 at 16:26 +0000, Luck, Tony wrote: > - pfn = PFN_DOWN(param1 & param2); > - if (!page_is_ram(pfn) || ((param2 & PAGE_MASK) != PAGE_MASK)) > + base_addr = param1 & param2; > + size = (~param2) + 1; > > We expect the user will supply us with param2 in the form 0xffffffff[fec8]00000 > with various numbers of leading 'f' and trailing '0' ... but I don't think we actually > check that anywhere. But we have a bunch of places that assume it is OK, including > this new one. > > It's time to fix that. Maybe even provide a default 0xfffffffffffff000 so I can save > myself some typing? + if (((region_intersects_ram(base_addr, size) != REGION_INTERSECTS) && + (region_intersects_pmem(base_addr, size) != REGION_INTERSECTS)) || + ((param2 & PAGE_MASK) != PAGE_MASK)) return -EINVAL; The 3rd condition check makes sure that the param2 mask is the page size or less. So, I think we are OK on this. Thanks, -Toshi -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>