On Wed, 18 Aug 2021 14:40:20 -0700 Kees Cook <keescook@xxxxxxxxxxxx> wrote: > As already done in GrapheneOS, add the __alloc_size attribute for > appropriate percpu allocator interfaces, to provide additional hinting > for better bounds checking, assisting CONFIG_FORTIFY_SOURCE and other > compiler optimizations. > Caught one, I assume: In file included from ./include/linux/string.h:262, from ./include/linux/bitmap.h:11, from ./include/linux/cpumask.h:12, from ./arch/x86/include/asm/cpumask.h:5, from ./arch/x86/include/asm/msr.h:11, from ./arch/x86/include/asm/processor.h:22, from ./arch/x86/include/asm/cpufeature.h:5, from ./arch/x86/include/asm/thread_info.h:53, from ./include/linux/thread_info.h:60, from ./arch/x86/include/asm/preempt.h:7, from ./include/linux/preempt.h:78, from ./include/linux/spinlock.h:55, from ./include/linux/mmzone.h:8, from ./include/linux/gfp.h:6, from ./include/linux/slab.h:15, from drivers/misc/lkdtm/heap.c:7: In function 'memset', inlined from 'lkdtm_VMALLOC_LINEAR_OVERFLOW' at drivers/misc/lkdtm/heap.c:27:2: ./include/linux/fortify-string.h:172:3: error: call to '__write_overflow' declared with attribute error: detected write beyond size of object passed as 1st parameter 172 | __write_overflow(); | ^~~~~~~~~~~~~~~~~~ make[3]: *** [drivers/misc/lkdtm/heap.o] Error 1 make[2]: *** [drivers/misc/lkdtm] Error 2 make[1]: *** [drivers/misc] Error 2 make: *** [drivers] Error 2 I want to get a kernel release out, so I'll hide mm-vmalloc-add-__alloc_size-attributes-for-better-bounds-checking.patch for now.