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).
As found with Coccinelle[1], add __counted_by for struct ct_incoming_msg. Cc: Jani Nikula <jani.nik...@linux.intel.com> Cc: Joonas Lahtinen <joonas.lahti...@linux.intel.com> Cc: Rodrigo Vivi <rodrigo.v...@intel.com> Cc: Tvrtko Ursulin <tvrtko.ursu...@linux.intel.com> Cc: David Airlie <airl...@gmail.com> Cc: Daniel Vetter <dan...@ffwll.ch> Cc: "Gustavo A. R. Silva" <gustavo...@kernel.org> Cc: John Harrison <john.c.harri...@intel.com> Cc: Matthew Brost <matthew.br...@intel.com> Cc: Michal Wajdeczko <michal.wajdec...@intel.com> Cc: Matt Roper <matthew.d.ro...@intel.com> Cc: intel-...@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org Cc: linux-harden...@vger.kernel.org Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1] Signed-off-by: Kees Cook <keesc...@chromium.org> --- drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c index 6e22af31513a..c33210ead1ef 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c @@ -96,7 +96,7 @@ struct ct_request { struct ct_incoming_msg { struct list_head link; u32 size; - u32 msg[]; + u32 msg[] __counted_by(size); }; enum { CTB_SEND = 0, CTB_RECV = 1 }; -- 2.34.1
