Patch "tracing: Fix parsing of globs with a wildcard at the beginning" has been added to the 4.15-stable tree

[<gregkh@linuxfoundation.org>]

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

    tracing: Fix parsing of globs with a wildcard at the beginning

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:
     tracing-fix-parsing-of-globs-with-a-wildcard-at-the-beginning.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 <stable@vger.kernel.org> know about it.


>From 07234021410bbc27b7c86c18de98616c29fbe667 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Date: Mon, 5 Feb 2018 22:18:11 -0500
Subject: tracing: Fix parsing of globs with a wildcard at the beginning

From: Steven Rostedt (VMware) <rostedt@goodmis.org>

commit 07234021410bbc27b7c86c18de98616c29fbe667 upstream.

Al Viro reported:

    For substring - sure, but what about something like "*a*b" and "a*b"?
    AFAICS, filter_parse_regex() ends up with identical results in both
    cases - MATCH_GLOB and *search = "a*b".  And no way for the caller
    to tell one from another.

Testing this with the following:

 # cd /sys/kernel/tracing
 # echo '*raw*lock' > set_ftrace_filter
 bash: echo: write error: Invalid argument

With this patch:

 # echo '*raw*lock' > set_ftrace_filter
 # cat set_ftrace_filter
_raw_read_trylock
_raw_write_trylock
_raw_read_unlock
_raw_spin_unlock
_raw_write_unlock
_raw_spin_trylock
_raw_spin_lock
_raw_write_lock
_raw_read_lock

Al recommended not setting the search buffer to skip the first '*' unless we
know we are not using MATCH_GLOB. This implements his suggested logic.

Link: http://lkml.kernel.org/r/20180127170748.GF13338@ZenIV.linux.org.uk

Cc: stable@vger.kernel.org
Fixes: 60f1d5e3bac44 ("ftrace: Support full glob matching")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Suggsted-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 kernel/trace/trace_events_filter.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -400,7 +400,6 @@ enum regex_type filter_parse_regex(char
 	for (i = 0; i < len; i++) {
 		if (buff[i] == '*') {
 			if (!i) {
-				*search = buff + 1;
 				type = MATCH_END_ONLY;
 			} else if (i == len - 1) {
 				if (type == MATCH_END_ONLY)
@@ -410,14 +409,14 @@ enum regex_type filter_parse_regex(char
 				buff[i] = 0;
 				break;
 			} else {	/* pattern continues, use full glob */
-				type = MATCH_GLOB;
-				break;
+				return MATCH_GLOB;
 			}
 		} else if (strchr("[?\\", buff[i])) {
-			type = MATCH_GLOB;
-			break;
+			return MATCH_GLOB;
 		}
 	}
+	if (buff[0] == '*')
+		*search = buff + 1;
 
 	return type;
 }


Patches currently in stable-queue which might be from rostedt@goodmis.org are

queue-4.15/trace_uprobe-display-correct-offset-in-uprobe_events.patch
queue-4.15/tracing-fix-parsing-of-globs-with-a-wildcard-at-the-beginning.patch