[PATCH 4.4 180/230] tracing: Do not free iter->trace in fail path of tracing_open_pipe()

From: Greg Kroah-Hartman
Date: Fri Mar 22 2019 - 07:36:27 EST

4.4-stable review patch. If anyone has any objections, please let me know.


From: zhangyi (F) <yi.zhang@xxxxxxxxxx>

commit e7f0c424d0806b05d6f47be9f202b037eb701707 upstream.

Commit d716ff71dd12 ("tracing: Remove taking of trace_types_lock in
pipe files") use the current tracer instead of the copy in
tracing_open_pipe(), but it forget to remove the freeing sentence in
the error path.

There's an error path that can call kfree(iter->trace) after the iter->trace
was assigned to tr->current_trace, which would be bad to free.

Link: http://lkml.kernel.org/r/1550060946-45984-1-git-send-email-yi.zhang@xxxxxxxxxx

Cc: stable@xxxxxxxxxxxxxxx
Fixes: d716ff71dd12 ("tracing: Remove taking of trace_types_lock in pipe files")
Signed-off-by: zhangyi (F) <yi.zhang@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

kernel/trace/trace.c | 1 -
1 file changed, 1 deletion(-)

--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4646,7 +4646,6 @@ out:
return ret;

- kfree(iter->trace);