Patch "ftrace: Remove incorrect setting of glob search field" has been added to the 4.15-stable tree

This is a note to let you know that I've just added the patch titled

ftrace: Remove incorrect setting of glob search field

to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
ftrace-remove-incorrect-setting-of-glob-search-field.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: "Steven Rostedt (VMware)" <[email protected]>
Date: Mon, 5 Feb 2018 22:05:31 -0500
Subject: ftrace: Remove incorrect setting of glob search field

From: Steven Rostedt (VMware) <[email protected]>

commit 7b6586562708d2b3a04fe49f217ddbadbbbb0546 upstream.

__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).

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

@@ -4456,7 +4456,6 @@ unregister_ftrace_function_probe_func(ch
 		func_g.type = filter_parse_regex(glob, strlen(glob),
 						 &func_g.search, &not);
 		func_g.len = strlen(func_g.search);
-		func_g.search = glob;
 
 		/* we do not support '!' for function probes */
 		if (WARN_ON(not))

Patches currently in stable-queue which might be from [email protected] are

queue-4.15/sched-rt-use-container_of-to-get-root-domain-in-rto_push_irq_work_func.patch queue-4.15/ftrace-remove-incorrect-setting-of-glob-search-field.patch queue-4.15/sched-rt-up-the-root-domain-ref-count-when-passing-it-around-via-ipis.patch