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 checking 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 fifo_buffer. [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci Cc: Philipp Reisner <philipp.reisner@xxxxxxxxxx> Cc: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx> Cc: "Christoph Böhmwalder" <christoph.boehmwalder@xxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: drbd-dev@xxxxxxxxxxxxxxxx Cc: linux-block@xxxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- drivers/block/drbd/drbd_int.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index a30a5ed811be..7eecc53fae3d 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -553,7 +553,7 @@ struct fifo_buffer { unsigned int head_index; unsigned int size; int total; /* sum of all values */ - int values[]; + int values[] __counted_by(size); }; extern struct fifo_buffer *fifo_alloc(unsigned int fifo_size); -- 2.34.1
