ftrace: Test for NULL iter->tr in regex for stack_trace_filter changes
authorSteven Rostedt (VMware) <rostedt@goodmis.org>
Wed, 5 Jul 2017 13:45:43 +0000 (09:45 -0400)
committerSteven Rostedt (VMware) <rostedt@goodmis.org>
Wed, 5 Jul 2017 13:52:18 +0000 (09:52 -0400)
commit69d71879d2cf67a381055f698a1d7def00dc4ed7
treebfca8b6145348c973eb6c880e614c22a6a2065e0
parent4dce17b26b6ac3bf29aa0eae1d28e14debe37747
ftrace: Test for NULL iter->tr in regex for stack_trace_filter changes

As writing into stack_trace_filter, the iter-tr is not set and is NULL.
Check if it is NULL before dereferencing it in ftrace_regex_release().

Fixes: 8c08f0d5c6fb ("ftrace: Have cached module filters be an active filter")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
kernel/trace/ftrace.c