On Tue, Jul 27, 2021 at 02:14:37PM +0100, Matthew Wilcox wrote: > On Tue, Jul 27, 2021 at 02:56:53PM +0200, Greg Kroah-Hartman wrote: > > And my mistake from earlier, size_t is the same as unsigned int, not > > unsigned long. > > No. > > include/linux/types.h:typedef __kernel_size_t size_t; > > include/uapi/asm-generic/posix_types.h: > > #ifndef __kernel_size_t > #if __BITS_PER_LONG != 64 > typedef unsigned int __kernel_size_t; > #else > typedef __kernel_ulong_t __kernel_size_t; > #endif > #endif > > size_t is an unsigned long on 64-bit, unless otherwise defined by the > arch. ugh, ok, so there really is a problem, as we have a size_t value being passed in as an int, and then it could be treated as a negative value for some fun pointer math to copy buffers around. How is this not causing problems now already? Are we just getting lucky? thanks, greg k-h
