1 files changed, 4 insertions, 0 deletions

diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index a05524fa245d..f64fbaae781a 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -648,6 +648,9 @@ __attribute__((section("_ftrace_events"))) event_##call = {		\
  *              char raw_data[__entry_size]; <- allocate our sample in the stack
  *              struct trace_entry *ent;
  *
+ *              zero dead bytes from alignment to avoid stack leak to userspace:
+ *
+ *              *(u64 *)(&raw_data[__entry_size - sizeof(u64)]) = 0ULL;
  *              entry = (struct ftrace_raw_<call> *)raw_data;
  *              ent = &entry->ent;
  *              tracing_generic_entry_update(ent, irq_flags, pc);
@@ -698,6 +701,7 @@ static void ftrace_profile_##call(proto)				\
                 char raw_data[__entry_size];                            \
                 struct trace_entry *ent;                                \
                                                                         \
+                *(u64 *)(&raw_data[__entry_size - sizeof(u64)]) = 0ULL; \
                 entry = (struct ftrace_raw_##call *)raw_data;           \
                 ent = &entry->ent;                                      \
                 tracing_generic_entry_update(ent, irq_flags, pc);       \