Alexey pointed out that defining a prctl flag as an int is a footgun
because, under some circumstances, when used as a flag to prctl, it can
be casted to long with garbage upper bits which would result in
unexpected behaviors.
This patch changes the constant to a UL to eliminate these
possibilities.
Signed-off-by: Florent Revest <revest@xxxxxxxxxxxx>
Suggested-by: Alexey Izbyshev <izbyshev@xxxxxxxxx>
---
include/uapi/linux/prctl.h | 2 +-
tools/include/uapi/linux/prctl.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h
index f23d9a16507f..6e9af6cbc950 100644
--- a/include/uapi/linux/prctl.h
+++ b/include/uapi/linux/prctl.h
@@ -283,7 +283,7 @@ struct prctl_mm_map {
/* Memory deny write / execute */
#define PR_SET_MDWE 65
-# define PR_MDWE_REFUSE_EXEC_GAIN 1
+# define PR_MDWE_REFUSE_EXEC_GAIN (1UL << 0)
#define PR_GET_MDWE 66
diff --git a/tools/include/uapi/linux/prctl.h b/tools/include/uapi/linux/prctl.h
index 759b3f53e53f..6e6563e97fef 100644
--- a/tools/include/uapi/linux/prctl.h
+++ b/tools/include/uapi/linux/prctl.h
@@ -283,7 +283,7 @@ struct prctl_mm_map {
/* Memory deny write / execute */
#define PR_SET_MDWE 65
-# define PR_MDWE_REFUSE_EXEC_GAIN 1
+# define PR_MDWE_REFUSE_EXEC_GAIN (1UL << 0)
#define PR_GET_MDWE 66
--
2.40.1.606.ga4b1b128d6-goog
