[PATCH v5 15/15] exec: Consolidate pdeath_signal clearing

From: Kees Cook
Date: Tue Aug 01 2017 - 15:17:40 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>
Acked-by: Serge Hallyn <serge@xxxxxxxxxx>
---
fs/exec.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/fs/exec.c b/fs/exec.c
index 3235cbd85efa..01a9fb9d8ac3 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1351,6 +1351,9 @@ void setup_new_exec(struct linux_binprm * bprm)
bprm->secureexec |= bprm->cap_elevated;

if (bprm->secureexec) {
+ /* Make sure parent cannot signal privileged process. */
+ current->pdeath_signal = 0;
+
/*
* For secureexec, reset the stack limit to sane default to
* avoid bad behavior from the prior rlimits. This has to
@@ -1383,10 +1386,6 @@ 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