Re: [PATCH] clone3: fix cgroup argument sanity check

From: Christian Brauner
Date: Wed Apr 15 2020 - 08:39:44 EST


On Sun, Apr 12, 2020 at 10:25:33PM +0200, Eugene Syromiatnikov wrote:
> Checking that cgroup field value of struct clone_args is less than 0
> is useless, as it is defined as unsigned 64-bit integer. Moreover,
> it doesn't catch the situations where its higher bits are lost during
> the assignment to the cgroup field of the cgroup field of the internal
> struct kernel_clone_args (where it is declared as signed 32-bit
> integer), so it is still possible to pass garbage there. A check
> against INT_MAX solves both these issues.
>
> Fixes: ef2c41cf38a7559b ("clone3: allow spawning processes into cgroups")
> Signed-off-by: Eugene Syromiatnikov <esyr@xxxxxxxxxx>
> Acked-by: Christian Brauner <christian.brauner@xxxxxxxxxx>

Applied, thanks!
Christian