tracehook: tracehook_tracer_task
This adds the tracehook_tracer_task() hook to consolidate all forms of
"Who is using ptrace on me?" logic. This is used for "TracerPid:" in
/proc and for permission checks. We also clean up the selinux code the
called an identical accessor.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/proc/base.c b/fs/proc/base.c
index a891fe4..4b74dba 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -69,6 +69,7 @@
#include <linux/mount.h>
#include <linux/security.h>
#include <linux/ptrace.h>
+#include <linux/tracehook.h>
#include <linux/cgroup.h>
#include <linux/cpuset.h>
#include <linux/audit.h>
@@ -231,10 +232,14 @@
* If current is actively ptrace'ing, and would also be
* permitted to freshly attach with ptrace now, permit it.
*/
- if (task->parent == current && (task->ptrace & PT_PTRACED) &&
- task_is_stopped_or_traced(task) &&
- ptrace_may_access(task, PTRACE_MODE_ATTACH))
- return 0;
+ if (task_is_stopped_or_traced(task)) {
+ int match;
+ rcu_read_lock();
+ match = (tracehook_tracer_task(task) == current);
+ rcu_read_unlock();
+ if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH))
+ return 0;
+ }
/*
* Noone else is allowed.