On (23/10/09 12:52), Kees Cook wrote: > On Mon, Oct 09, 2023 at 12:42:05PM -0600, Gustavo A. R. Silva wrote: > > Array `data` in `struct hfi_sfr` is being used as a fake flexible array > > at run-time: > > > > drivers/media/platform/qcom/venus/hfi_venus.c: > > 1033 p = memchr(sfr->data, '\0', sfr->buf_size); > > 1034 /* > > 1035 * SFR isn't guaranteed to be NULL terminated since SYS_ERROR indicates > > 1036 * that Venus is in the process of crashing. > > 1037 */ > > 1038 if (!p) > > 1039 sfr->data[sfr->buf_size - 1] = '\0'; > > 1040 > > 1041 dev_err_ratelimited(dev, "SFR message from FW: %s\n", sfr->data); > > > > Fake flexible arrays are deprecated, and should be replaced by > > flexible-array members. So, replace one-element array with a > > flexible-array member in `struct hfi_sfr`. > > > > While there, also annotate array `data` with __counted_by() to 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). > > > > This results in no differences in binary output. > > Thanks for checking! Sorry for shameless plug, a quick question: has any compiler implemented support for counted_by() at this point?
