Yama: higher restrictions should block PTRACE_TRACEME

The higher ptrace restriction levels should be blocking even
PTRACE_TRACEME requests. The comments in the LSM documentation are
misleading about when the checks happen (the parent does not go through
security_ptrace_access_check() on a PTRACE_TRACEME call).

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org # 3.5.x and later
Signed-off-by: James Morris <james.l.morris@oracle.com>

1 files changed, 0 insertions, 2 deletions

diff --git a/include/linux/security.h b/include/linux/security.h
index 4e5a73cdbbef..3dea6a9d568f 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1242,8 +1242,6 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
  *      Check that the @parent process has sufficient permission to trace the
  *      current process before allowing the current process to present itself
  *      to the @parent process for tracing.
- *      The parent process will still have to undergo the ptrace_access_check
- *      checks before it is allowed to trace this one.
  *      @parent contains the task_struct structure for debugger process.
  *      Return 0 if permission is granted.
  * @capget: