FORTIFY_SOURCE has been ignoring 0-sized destinations while the kernel code base has been converted to flexible arrays. In order to enforce the 0-sized destinations (e.g. with __counted_by), the remaining 0-sized destinations need to be handled. Instead of converting an empty struct into using a flexible array, just directly use a pointer without any additional indirection. Remove struct gb_bootrom_get_firmware_response and struct gb_fw_download_fetch_firmware_response.
Signed-off-by: Kees Cook keescook@chromium.org --- Cc: Alex Elder elder@kernel.org Cc: Viresh Kumar vireshk@kernel.org Cc: Johan Hovold johan@kernel.org Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Gustavo A. R. Silva gustavo@embeddedor.com Cc: greybus-dev@lists.linaro.org Cc: linux-staging@lists.linux.dev v2: add comments about removed structs v1: https://patchwork.kernel.org/project/linux-hardening/patch/20240216232824.wo... --- drivers/staging/greybus/bootrom.c | 8 ++++---- drivers/staging/greybus/fw-download.c | 8 ++++---- include/linux/greybus/greybus_protocols.h | 8 ++------ 3 files changed, 10 insertions(+), 14 deletions(-)
diff --git a/drivers/staging/greybus/bootrom.c b/drivers/staging/greybus/bootrom.c index 79581457c4af..c0d338db6b52 100644 --- a/drivers/staging/greybus/bootrom.c +++ b/drivers/staging/greybus/bootrom.c @@ -243,10 +243,10 @@ static int gb_bootrom_get_firmware(struct gb_operation *op) struct gb_bootrom *bootrom = gb_connection_get_data(op->connection); const struct firmware *fw; struct gb_bootrom_get_firmware_request *firmware_request; - struct gb_bootrom_get_firmware_response *firmware_response; struct device *dev = &op->connection->bundle->dev; unsigned int offset, size; enum next_request_type next_request; + u8 *firmware_response; int ret = 0;
/* Disable timeouts */ @@ -280,15 +280,15 @@ static int gb_bootrom_get_firmware(struct gb_operation *op) goto unlock; }
- if (!gb_operation_response_alloc(op, sizeof(*firmware_response) + size, - GFP_KERNEL)) { + /* gb_bootrom_get_firmware_response contains only a byte array */ + if (!gb_operation_response_alloc(op, size, GFP_KERNEL)) { dev_err(dev, "%s: error allocating response\n", __func__); ret = -ENOMEM; goto unlock; }
firmware_response = op->response->payload; - memcpy(firmware_response->data, fw->data + offset, size); + memcpy(firmware_response, fw->data + offset, size);
dev_dbg(dev, "responding with firmware (offs = %u, size = %u)\n", offset, size); diff --git a/drivers/staging/greybus/fw-download.c b/drivers/staging/greybus/fw-download.c index 543692c567f9..a06065fb0c5e 100644 --- a/drivers/staging/greybus/fw-download.c +++ b/drivers/staging/greybus/fw-download.c @@ -271,11 +271,11 @@ static int fw_download_fetch_firmware(struct gb_operation *op) struct gb_connection *connection = op->connection; struct fw_download *fw_download = gb_connection_get_data(connection); struct gb_fw_download_fetch_firmware_request *request; - struct gb_fw_download_fetch_firmware_response *response; struct fw_request *fw_req; const struct firmware *fw; unsigned int offset, size; u8 firmware_id; + u8 *response; int ret = 0;
if (op->request->payload_size != sizeof(*request)) { @@ -325,8 +325,8 @@ static int fw_download_fetch_firmware(struct gb_operation *op) goto put_fw; }
- if (!gb_operation_response_alloc(op, sizeof(*response) + size, - GFP_KERNEL)) { + /* gb_fw_download_fetch_firmware_response contains only a byte array */ + if (!gb_operation_response_alloc(op, size, GFP_KERNEL)) { dev_err(fw_download->parent, "error allocating fetch firmware response\n"); ret = -ENOMEM; @@ -334,7 +334,7 @@ static int fw_download_fetch_firmware(struct gb_operation *op) }
response = op->response->payload; - memcpy(response->data, fw->data + offset, size); + memcpy(response, fw->data + offset, size);
dev_dbg(fw_download->parent, "responding with firmware (offs = %u, size = %u)\n", offset, diff --git a/include/linux/greybus/greybus_protocols.h b/include/linux/greybus/greybus_protocols.h index aeb8f9243545..820134b0105c 100644 --- a/include/linux/greybus/greybus_protocols.h +++ b/include/linux/greybus/greybus_protocols.h @@ -232,9 +232,7 @@ struct gb_fw_download_fetch_firmware_request { __le32 size; } __packed;
-struct gb_fw_download_fetch_firmware_response { - __u8 data[0]; -} __packed; +/* gb_fw_download_fetch_firmware_response contains no other data */
/* firmware download release firmware request */ struct gb_fw_download_release_firmware_request { @@ -414,9 +412,7 @@ struct gb_bootrom_get_firmware_request { __le32 size; } __packed;
-struct gb_bootrom_get_firmware_response { - __u8 data[0]; -} __packed; +/* gb_bootrom_get_firmware_response contains no other data */
/* Bootrom protocol Ready to boot request */ struct gb_bootrom_ready_to_boot_request {