On Mon, Oct 04, 2021 at 11:42:20PM +0100, Matthew Wilcox (Oracle) wrote: > We must prohibit page boundary crossing for kmap() addresses. > vmap() addresses are limited by the length of the mapping, and > compound pages are limited by the size of the page. > > These should probably all have test cases? > > Matthew Wilcox (Oracle) (3): > mm/usercopy: Check kmap addresses properly > mm/usercopy: Detect vmalloc overruns > mm/usercopy: Detect compound page overruns Thanks! This is a nice additional bit of checking. I wonder if the CMA and Reserved pieces should be extracted from the PAGESPAN check too? Probably that CONFIG should be renamed as well now. :P -Kees > > arch/x86/include/asm/highmem.h | 1 + > include/linux/highmem-internal.h | 10 ++++++++++ > mm/usercopy.c | 33 +++++++++++++++++++++----------- > 3 files changed, 33 insertions(+), 11 deletions(-) > > -- > 2.32.0 > -- Kees Cook
