[PATCH v2 7/8] exec: Consolidate pdeath_signal clearing

From: Kees Cook
Date: Mon Jul 10 2017 - 03:59:23 EST


Instead of an additional secureexec check for pdeath_signal, just move it
up into the initial secureexec test. Neither perf nor arch code touches
pdeath_signal, so the relocation shouldn't change anything.

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
fs/exec.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/fs/exec.c b/fs/exec.c
index eeb8323977d1..e0186db02f90 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1340,6 +1340,9 @@ void setup_new_exec(struct linux_binprm * bprm)
if (security_bprm_secureexec(bprm)) {
/* Record for AT_SECURE. */
bprm->secureexec = 1;
+
+ /* Make sure parent cannot signal privileged process. */
+ current->pdeath_signal = 0;
}

arch_pick_mmap_layout(current->mm);
@@ -1363,10 +1366,6 @@ void setup_new_exec(struct linux_binprm * bprm)
*/
current->mm->task_size = TASK_SIZE;

- if (bprm->secureexec) {
- current->pdeath_signal = 0;
- }
-
/* An exec changes our domain. We are no longer part of the thread
group */
current->self_exec_id++;
--
2.7.4