Re: [Linux-stable-mirror] [RFC][PATCH 1/6] ftrace: Remove incorrect setting of glob search field

2018-02-06 22:43 GMT+00:00 Steven Rostedt rostedt@goodmis.org:

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

__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@ZenIV.linux.org.uk

Cc: stable@vger.kernel.org Cc: Dmitry Safonov 0x7f454c46@gmail.com Fixes: 3ba009297149f ("ftrace: Introduce ftrace_glob structure") Reported-by: Al Viro viro@ZenIV.linux.org.uk Signed-off-by: Steven Rostedt (VMware) rostedt@goodmis.org

Reviewed-by: Dmitry Safonov 0x7f454c46@gmail.com Thank you, Steven.