tree 7e8e024bbed52ac111a0b2ac878da1a95752c28b
parent 5e751e992f3fb08ba35e1ca8095ec8fbf9eda523
author David Howells <dhowells@redhat.com> 1241787327 +0100
committer James Morris <jmorris@namei.org> 1241993739 +1000

CRED: Guard the setprocattr security hook against ptrace

Guard the setprocattr security hook against ptrace by taking the target task's
cred_guard_mutex around it.  The problem is that setprocattr() may otherwise
note the lack of a debugger, and then perform an action on that basis whilst
letting a debugger attach between the two points.  Holding cred_guard_mutex
across the test and the action prevents ptrace_attach() from doing that.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>