Cc csky developers. See https://lore.kernel.org/r/202501040747.S3LYfvYq-lkp@xxxxxxxxx On Mon, Jan 06, 2025 at 04:27:26PM -0800, Kees Cook wrote: > On Mon, Jan 06, 2025 at 06:04:56PM +0100, Mickaël Salaün wrote: > > On Sat, Jan 04, 2025 at 07:26:27AM +0800, kernel test robot wrote: > > > security/landlock/ruleset.c: In function 'create_rule': > > > >> security/landlock/ruleset.c:96:9: warning: 'memcpy' accessing 4294967295 bytes at offsets 20 and 0 overlaps 6442450943 bytes at offset -2147483648 [-Wrestrict] > > > 96 | memcpy(new_rule->layers, layers, > > > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > > 97 | flex_array_size(new_rule, layers, num_layers)); > > > | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This warning seems to only show with the csky architecture. > > > > I guess the GCC warning is a false positive? > > See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116494 > > Does the warning go away if flex_array_size() is open-coded or if the > create_rule prototype uses "*" instead of "[]" syntax for the "layers" > argument? But that would not be correct right? > > The warning is about the "read" part ("accessing"). Using tip-of-tree > gcc with -fdiagnostics-details might show more details on the calling > path. > > -Kees > > -- > Kees Cook >
