On Wed, Aug 09, 2023 at 03:45:03PM +0800, GONG, Ruiqi wrote:
> From: "GONG, Ruiqi" <gongruiqi1@xxxxxxxxxx>
>
> When compiling with gcc 13 and CONFIG_FORTIFY_SOURCE=y, the following
> warning appears:
>
> In function ‘fortify_memcpy_chk’,
> inlined from ‘size_entry_mwt’ at net/bridge/netfilter/ebtables.c:2118:2:
> ./include/linux/fortify-string.h:592:25: error: call to ‘__read_overflow2_field’
> declared with attribute warning: detected read beyond size of field (2nd parameter);
> maybe use struct_group()? [-Werror=attribute-warning]
> 592 | __read_overflow2_field(q_size_field, size);
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> The compiler is complaining:
>
> memcpy(&offsets[1], &entry->watchers_offset,
> sizeof(offsets) - sizeof(offsets[0]));
>
> where memcpy reads beyong &entry->watchers_offset to copy
> {watchers,target,next}_offset altogether into offsets[]. Silence the
> warning by wrapping these three up via struct_group().
>
> Signed-off-by: GONG, Ruiqi <gongruiqi1@xxxxxxxxxx>
If a v4 is sent, please fix the "beyong" typo that was pointed out.
Otherwise, it looks okay to me:
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
--
Kees Cook
