Commit 62173872 authored Apr 12, 2020 by Eugene Syromiatnikov Committed by Christian Brauner Apr 15, 2020

clone3: add a check for the user struct size if CLONE_INTO_CGROUP is set

Passing CLONE_INTO_CGROUP with an under-sized structure (that doesn't
properly contain cgroup field) seems like garbage input, especially
considering the fact that fd 0 is a valid descriptor.

Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20200412203123.GA5869@asgard.redhat.com

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

parent e82a118f

kernel/fork.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -2631,7 +2631,8 @@ noinline static int copy_clone_args_from_user(struct kernel_clone_args *kargs,
		!valid_signal(args.exit_signal)))
		return -EINVAL;

		if ((args.flags & CLONE_INTO_CGROUP) && args.cgroup > INT_MAX)
		if ((args.flags & CLONE_INTO_CGROUP) &&
		(args.cgroup > INT_MAX \|\| usize < CLONE_ARGS_SIZE_VER2))
		return -EINVAL;

		*kargs = (struct kernel_clone_args){