From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>
__unregister_ftrace_function_probe() will incorrectly parse the glob filter
because it resets the search variable that was setup by filter_parse_regex().
Al Viro reported this:
After that call of filter_parse_regex() we could have func_g.search not
equal to glob only if glob started with '!' or '*'. In the former case
we would've buggered off with -EINVAL (not = 1). In the latter we
would've set func_g.search equal to glob + 1, calculated the length of
that thing in func_g.len and proceeded to reset func_g.search back to
glob.
Suppose the glob is e.g. *foo*. We end up with
func_g.type = MATCH_MIDDLE_ONLY;
func_g.len = 3;
func_g.search = "*foo";
Feeding that to ftrace_match_record() will not do anything sane - we
will be looking for names containing "*foo" (->len is ignored for that
one).
Link: http://lkml.kernel.org/r/20180127031706.GE13338@xxxxxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Cc: Dmitry Safonov <0x7f454c46@xxxxxxxxx>
Fixes: 3ba009297149f ("ftrace: Introduce ftrace_glob structure")
Reported-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
kernel/trace/ftrace.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index dabd9d167d42..eac9ce2c57a2 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -4456,7 +4456,6 @@ unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
func_g.type = filter_parse_regex(glob, strlen(glob),
&func_g.search, ¬);
func_g.len = strlen(func_g.search);
- func_g.search = glob;
/* we do not support '!' for function probes */
if (WARN_ON(not))
--
2.15.1