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/ Cc: Rasmus Villemoes <rasmus.villemoes@xxxxxxxxx> Cc: Guenter Roeck <linux@xxxxxxxxxxxx> Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxx> Cc: Paolo Abeni <pabeni@xxxxxxxxxx> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- include/linux/fortify-string.h | 2 +- include/linux/string.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h index 9e2d96993c30..aa31f54f8b57 100644 --- a/include/linux/fortify-string.h +++ b/include/linux/fortify-string.h @@ -670,7 +670,7 @@ __FORTIFY_INLINE void *memchr_inv(const void * const POS0 p, int c, size_t size) } extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kmemdup) - __alloc_size(2); + __realloc_size(2); __FORTIFY_INLINE void *kmemdup(const void * const POS0 p, size_t size, gfp_t gfp) { size_t p_size = __struct_size(p); diff --git a/include/linux/string.h b/include/linux/string.h index af1d69e5610e..db28802ab0a6 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -176,7 +176,7 @@ extern void kfree_const(const void *x); extern char *kstrdup(const char *s, gfp_t gfp) __malloc; extern const char *kstrdup_const(const char *s, gfp_t gfp); 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); extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp); extern char **argv_split(gfp_t gfp, const char *str, int *argcp); -- 2.34.1
