tracing: Do not assign filp->private_data to freed memory
In system_tr_open(), the filp->private_data can be assigned the 'dir'
variable even if it was freed. This is on the error path, and is
harmless because the error return code will prevent filp->private_data
from being used. But for correctness, we should not assign it to
a recently freed variable, as that can cause static tools to give
false warnings.
Also have both subsystem_open() and system_tr_open() return -ENODEV
if tracing has been disabled.
Link: http://lkml.kernel.org/r/1383764571-7318-1-git-send-email-geyslan@gmail.com
Signed-off-by: Geyslan G. Bem <geyslan@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 043f833..f919a2e 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1062,6 +1062,9 @@
struct trace_array *tr;
int ret;
+ if (tracing_is_disabled())
+ return -ENODEV;
+
/* Make sure the system still exists */
mutex_lock(&trace_types_lock);
mutex_lock(&event_mutex);
@@ -1108,6 +1111,9 @@
struct trace_array *tr = inode->i_private;
int ret;
+ if (tracing_is_disabled())
+ return -ENODEV;
+
if (trace_array_get(tr) < 0)
return -ENODEV;
@@ -1124,11 +1130,12 @@
if (ret < 0) {
trace_array_put(tr);
kfree(dir);
+ return ret;
}
filp->private_data = dir;
- return ret;
+ return 0;
}
static int subsystem_release(struct inode *inode, struct file *file)