On Thu, 28 Mar 2024 at 21:58, Richard Fung <richardfung@xxxxxxxxxx> wrote:
>
> This adds support for the FS_IOC_ENABLE_VERITY and FS_IOC_MEASURE_VERITY
> ioctls. The FS_IOC_READ_VERITY_METADATA is missing but from the
> documentation, "This is a fairly specialized use case, and most fs-verity
> users won’t need this ioctl."
>
> Signed-off-by: Richard Fung <richardfung@xxxxxxxxxx>
> ---
> fs/fuse/ioctl.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 52 insertions(+)
>
> diff --git a/fs/fuse/ioctl.c b/fs/fuse/ioctl.c
> index 726640fa439e..a0e86c3de48f 100644
> --- a/fs/fuse/ioctl.c
> +++ b/fs/fuse/ioctl.c
> @@ -8,6 +8,7 @@
> #include <linux/uio.h>
> #include <linux/compat.h>
> #include <linux/fileattr.h>
> +#include <linux/fsverity.h>
>
> static ssize_t fuse_send_ioctl(struct fuse_mount *fm, struct fuse_args *args,
> struct fuse_ioctl_out *outarg)
> @@ -227,6 +228,57 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
> out_iov = iov;
> out_iovs = 1;
> }
> +
> + /* For fs-verity, determine iov lengths from input */
> + switch (cmd) {
> + case FS_IOC_MEASURE_VERITY: {
> + __u16 digest_size;
> + struct fsverity_digest __user *uarg =
> + (struct fsverity_digest __user *)arg;
> +
> + if (copy_from_user(&digest_size, &uarg->digest_size,
> + sizeof(digest_size)))
> + return -EFAULT;
> +
> + if (digest_size > SIZE_MAX - sizeof(struct fsverity_digest))
> + return -EINVAL;
> +
> + iov->iov_len = sizeof(struct fsverity_digest) + digest_size;
> + break;
> + }
> + case FS_IOC_ENABLE_VERITY: {
> + struct fsverity_enable_arg enable;
> + struct fsverity_enable_arg __user *uarg =
> + (struct fsverity_enable_arg __user *)arg;
> + const __u32 max_buffer_len = FUSE_MAX_MAX_PAGES * PAGE_SIZE;
> +
> + if (copy_from_user(&enable, uarg, sizeof(enable)))
> + return -EFAULT;
> +
> + if (enable.salt_size > max_buffer_len ||
> + enable.sig_size > max_buffer_len)
> + return -ENOMEM;
> +
> + if (enable.salt_size > 0) {
> + iov++;
> + in_iovs++;
> +
> + iov->iov_base = u64_to_user_ptr(enable.salt_ptr);
> + iov->iov_len = enable.salt_size;
> + }
> +
> + if (enable.sig_size > 0) {
> + iov++;
> + in_iovs++;
> +
> + iov->iov_base = u64_to_user_ptr(enable.sig_ptr);
> + iov->iov_len = enable.sig_size;
> + }
> + break;
> + }
> + default:
> + break;
> + }
> }
>
> retry:
I'm not thrilled by having ioctl specific handling added to the
generic fuse ioctl code.
But more important is what the fsverity folks think (CC's added).
Thanks,
Miklos
