On Mon, Oct 09, 2023 at 03:52:59PM -0600, Gustavo A. R. Silva wrote:
Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).
While there, use struct_size() helper, instead of the open-coded version, to calculate the size for the allocation of the whole flexible structure, including of course, the flexible-array member.
This code was found with the help of Coccinelle, and audited and fixed manually.
Signed-off-by: Gustavo A. R. Silva gustavoars@kernel.org
Looks right, "len" is updated before accessing "data[]".
Reviewed-by: Kees Cook keescook@chromium.org