From 69d71879d2cf67a381055f698a1d7def00dc4ed7 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Wed, 5 Jul 2017 09:45:43 -0400 Subject: [PATCH] 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) --- kernel/trace/ftrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index f8c18f15b190..2953d558bbee 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -5043,7 +5043,7 @@ int ftrace_regex_release(struct inode *inode, struct file *file) if (filter_hash) { orig_hash = &iter->ops->func_hash->filter_hash; - if (!list_empty(&iter->tr->mod_trace)) + if (iter->tr && !list_empty(&iter->tr->mod_trace)) iter->hash->flags |= FTRACE_HASH_FL_MOD; } else orig_hash = &iter->ops->func_hash->notrace_hash; -- 2.20.1