On 01/11/2022 23.33, Kees Cook wrote: > Add __realloc_size() hint to kmemdup() so the compiler can reason about > the length of the returned buffer. (These must not use __alloc_size, > since those include __malloc which says the contents aren't defined[1]). > > [1] https://lore.kernel.org/linux-hardening/d199c2af-06af-8a50-a6a1-00eefa0b67b4@xxxxxxxxx/ > > extern char *kstrndup(const char *s, size_t len, gfp_t gfp); > -extern void *kmemdup(const void *src, size_t len, gfp_t gfp) __alloc_size(2); > +extern void *kmemdup(const void *src, size_t len, gfp_t gfp) __realloc_size(2); What tree is this based on? I see that kmemdup() has grown that bogus __alloc_size in next-20221101, but in next-20221102 this commit seems to DTRT, namely -extern void *kmemdup(const void *src, size_t len, gfp_t gfp); +extern void *kmemdup(const void *src, size_t len, gfp_t gfp) __realloc_size(2); (i.e. there should never be an intermediate commit where kmemdup has __alloc_size()). Rasmus
