From 62173872ca65767c586217dec0a32485da8a2f07 Mon Sep 17 00:00:00 2001 From: Eugene Syromiatnikov Date: Sun, 12 Apr 2020 22:31:23 +0200 Subject: [PATCH] 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 Acked-by: Christian Brauner Link: https://lore.kernel.org/r/20200412203123.GA5869@asgard.redhat.com Signed-off-by: Christian Brauner --- kernel/fork.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/fork.c b/kernel/fork.c index b4f7775623c8..3ab7cf88e455 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -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){ -- 2.11.0