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 <[email protected]> Cc: Joonas Lahtinen <[email protected]> Cc: Rodrigo Vivi <[email protected]> Cc: Tvrtko Ursulin <[email protected]> Cc: David Airlie <[email protected]> Cc: Daniel Vetter <[email protected]> Cc: "Gustavo A. R. Silva" <[email protected]> Cc: John Harrison <[email protected]> Cc: Matthew Brost <[email protected]> Cc: Michal Wajdeczko <[email protected]> Cc: Matt Roper <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1] Signed-off-by: Kees Cook <[email protected]> --- 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
