Commit 4213e92e authored by Gustavo A. R. Silva's avatar Gustavo A. R. Silva Committed by Greg Kroah-Hartman
Browse files

usb: gadget: f_fs: Use struct_size() and flex_array_size() helpers 

Make use of the struct_size() and flex_array_size() helpers instead of
an open-coded version, in order to avoid any potential type mistakes
or integer overflows that, in the worst scenario, could lead to heap
overflows.

Also, address the following sparse warnings:
drivers/usb/gadget/function/f_fs.c:922:23: warning: using sizeof on a flexible structure

Link: https://github.com/KSPP/linux/issues/174


Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarGustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20220120222933.GA35155@embeddedor


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7643fd78

drivers/usb/gadget/function/f_fs.c

+2 −2
Original line number Diff line number Diff line
@@ -919,12 +919,12 @@ static ssize_t __ffs_epfile_read_data(struct ffs_epfile *epfile, 
		data_len, ret);



	data_len -= ret;

	buf = kmalloc(sizeof(*buf) + data_len, GFP_KERNEL);

	buf = kmalloc(struct_size(buf, storage, data_len), GFP_KERNEL);

	if (!buf)

		return -ENOMEM;

	buf->length = data_len;

	buf->data = buf->storage;

	memcpy(buf->storage, data + ret, data_len);

	memcpy(buf->storage, data + ret, flex_array_size(buf, storage, data_len));



	/*

	 * At this point read_buffer is NULL or READ_BUFFER_DROP (if