On 10/12/2021 11:06 AM, Vivek Goyal wrote:
> Add the FUSE_SECURITY_CTX flag for the `flags` field of the
> fuse_init_out struct. When this flag is set the kernel will append the
> security context for a newly created inode to the request (create,
> mkdir, mknod, and symlink). The server is responsible for ensuring that
> the inode appears atomically (preferrably) with the requested security context.
>
> For example, if the server is backed by a "real" linux file system then
> it can write the security context value to
> /proc/thread-self/attr/fscreate before making the syscall to create the
> inode.
his only works for SELinux, as I've mentioned before. Perhaps:
If the server is using SELinux and backed by a "real" linux file system
that supports extended attributes it can write the security context value
to /proc/thread-self/attr/fscreate before making the syscall to create
the inode.
>
> Vivek:
> This patch is slightly modified version of patch from
> Chirantan Ekbote <chirantan@xxxxxxxxxxxx>. I made changes so that this
> patch applies to latest kernel.
>
> Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
> ---
> include/uapi/linux/fuse.h | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
> index 36ed092227fa..2fe54c80051a 100644
> --- a/include/uapi/linux/fuse.h
> +++ b/include/uapi/linux/fuse.h
> @@ -184,6 +184,10 @@
> *
> * 7.34
> * - add FUSE_SYNCFS
> + *
> + * 7.35
> + * - add FUSE_SECURITY_CTX flag for fuse_init_out
> + * - add security context to create, mkdir, symlink, and mknod requests
> */
>
> #ifndef _LINUX_FUSE_H
> @@ -219,7 +223,7 @@
> #define FUSE_KERNEL_VERSION 7
>
> /** Minor version number of this interface */
> -#define FUSE_KERNEL_MINOR_VERSION 34
> +#define FUSE_KERNEL_MINOR_VERSION 35
>
> /** The node ID of the root inode */
> #define FUSE_ROOT_ID 1
> @@ -336,6 +340,8 @@ struct fuse_file_lock {
> * write/truncate sgid is killed only if file has group
> * execute permission. (Same as Linux VFS behavior).
> * FUSE_SETXATTR_EXT: Server supports extended struct fuse_setxattr_in
> + * FUSE_SECURITY_CTX: add security context to create, mkdir, symlink, and
> + * mknod
> */
> #define FUSE_ASYNC_READ (1 << 0)
> #define FUSE_POSIX_LOCKS (1 << 1)
> @@ -367,6 +373,7 @@ struct fuse_file_lock {
> #define FUSE_SUBMOUNTS (1 << 27)
> #define FUSE_HANDLE_KILLPRIV_V2 (1 << 28)
> #define FUSE_SETXATTR_EXT (1 << 29)
> +#define FUSE_SECURITY_CTX (1 << 30)
>
> /**
> * CUSE INIT request/reply flags
