Re: [RFC PATCH ghak32 V2 02/13] audit: check children and threading before allowing containerid

[Paul Moore]

On Fri, Mar 16, 2018 at 5:00 AM, Richard Guy Briggs  wrote:
> Check if a task has existing children or co-threads and refuse to set
> the container ID if either are present.  Failure to check this could
> permit games where a child scratches its parent's back to work around
> inheritance and double-setting policy.
>
> Signed-off-by: Richard Guy Briggs 
> ---
>  kernel/auditsc.c | 4 
>  1 file changed, 4 insertions(+)

I would just include this in patch 1/2 as I can't think of world where
we wouldn't this check.

> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 29c8482..a6b0a52 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -2087,6 +2087,10 @@ static int audit_set_containerid_perm(struct 
> task_struct *task, u64 containerid)
> /* if we don't have caps, reject */
> if (!capable(CAP_AUDIT_CONTROL))
> return -EPERM;
> +   /* if task has children or is not single-threaded, deny */
> +   if (!list_empty(>children) ||
> +   !(thread_group_leader(task) && thread_group_empty(task)))
> +   return -EPERM;
> /* if containerid is unset, allow */
> if (!audit_containerid_set(task))
> return 0;
> --
> 1.8.3.1

-- 
paul moore
www.paul-moore.com

--
Linux-audit mailing list
Linux-audit@redhat.com
https://www.redhat.com/mailman/listinfo/linux-audit

[RFC PATCH ghak32 V2 02/13] audit: check children and threading before allowing containerid

[Richard Guy Briggs]

Check if a task has existing children or co-threads and refuse to set
the container ID if either are present.  Failure to check this could
permit games where a child scratches its parent's back to work around
inheritance and double-setting policy.

Signed-off-by: Richard Guy Briggs 
---
 kernel/auditsc.c | 4 
 1 file changed, 4 insertions(+)

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 29c8482..a6b0a52 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2087,6 +2087,10 @@ static int audit_set_containerid_perm(struct task_struct 
*task, u64 containerid)
/* if we don't have caps, reject */
if (!capable(CAP_AUDIT_CONTROL))
return -EPERM;
+   /* if task has children or is not single-threaded, deny */
+   if (!list_empty(>children) ||
+   !(thread_group_leader(task) && thread_group_empty(task)))
+   return -EPERM;
/* if containerid is unset, allow */
if (!audit_containerid_set(task))
return 0;
-- 
1.8.3.1

--
Linux-audit mailing list
Linux-audit@redhat.com
https://www.redhat.com/mailman/listinfo/linux-audit