From: Steven Rostedt (VMware) Date: Wed, 5 Jul 2017 13:45:43 +0000 (-0400) Subject: ftrace: Test for NULL iter->tr in regex for stack_trace_filter changes X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=69d71879d2cf67a381055f698a1d7def00dc4ed7;p=openwrt%2Fstaging%2Fblogic.git 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) --- 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;