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Commit d6d3523c authored by Geyslan G. Bem's avatar Geyslan G. Bem Committed by Steven Rostedt
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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: default avatarGeyslan G. Bem <geyslan@gmail.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 2e86421d

kernel/trace/trace_events.c

+8 −1
Original line number Diff line number Diff line
@@ -1062,6 +1062,9 @@ static int subsystem_open(struct inode *inode, struct file *filp) 
	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 @@ static int system_tr_open(struct inode *inode, struct file *filp) 
	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 @@ static int system_tr_open(struct inode *inode, struct file *filp) 
	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)