security: Yama LSM

This adds the Yama Linux Security Module to collect DAC security
improvements (specifically just ptrace restrictions for now) that have
existed in various forms over the years and have been carried outside the
mainline kernel by other Linux distributions like Openwall and grsecurity.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/prctl.h b/include/linux/prctl.h
index 7ddc7f1b480f..4d0e5bc5458c 100644
--- a/include/linux/prctl.h
+++ b/include/linux/prctl.h
@@ -114,4 +114,10 @@
 # define PR_SET_MM_START_BRK            6
 # define PR_SET_MM_BRK                  7
 
+/*
+ * Set specific pid that is allowed to ptrace the current task.
+ * A value of 0 mean "no process".
+ */
+#define PR_SET_PTRACER 0x59616d61
+
 #endif /* _LINUX_PRCTL_H */