[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20240725131632.64cab267@gandalf.local.home>
Date: Thu, 25 Jul 2024 13:16:32 -0400
From: Steven Rostedt <rostedt@...dmis.org>
To: Ajay Kaher <ajay.kaher@...adcom.com>
Cc: Mathias Krause <minipli@...ecurity.net>, Masami Hiramatsu
<mhiramat@...nel.org>, Ilkka Naulapää
<digirigawa@...il.com>, Linus Torvalds <torvalds@...ux-foundation.org>, Al
Viro <viro@...iv.linux.org.uk>, linux-trace-kernel@...r.kernel.org,
linux-kernel@...r.kernel.org, regressions@...mhuis.info, Dan Carpenter
<dan.carpenter@...aro.org>, Vasavi Sirnapalli
<vasavi.sirnapalli@...adcom.com>, Alexey Makhalov
<alexey.makhalov@...adcom.com>, Florian Fainelli
<florian.fainelli@...adcom.com>
Subject: Re: tracing: user events UAF crash report
On Thu, 25 Jul 2024 13:10:21 -0400
Steven Rostedt <rostedt@...dmis.org> wrote:
>
> diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
> index 3a2b46847c8b..e9ed2826ff46 100644
> --- a/kernel/trace/trace_events_user.c
> +++ b/kernel/trace/trace_events_user.c
> @@ -321,6 +321,8 @@ static void user_event_put(struct user_event *user, bool locked)
> */
> refcount_set(&user->refcnt, 1);
>
> + user->call.data = NULL;
Hmm, it may be possible to just have:
user->call.get_fields = NULL;
and then it will just use the call->class->fields instead and that should
be initialized to empty.
-- Steve
> +
> if (WARN_ON_ONCE(!schedule_work(&user->put_work))) {
> /*
> * If we fail we must wait for an admin to attempt delete or
> @@ -973,6 +975,11 @@ size_t copy_nofault(void *addr, size_t bytes, struct iov_iter *i)
> static struct list_head *user_event_get_fields(struct trace_event_call *call)
> {
> struct user_event *user = (struct user_event *)call->data;
> + static LIST_HEAD(head);
> +
> + /* If the user event is about to be deleted, return no fields */
> + if (!user)
> + return &head;
>
> return &user->fields;
> }
Powered by blists - more mailing lists