linux-kernel - [PATCH 5.15 551/667] tracing: Fix potential double free in create_var

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20220607164951.225881821@linuxfoundation.org>
Date:   Tue,  7 Jun 2022 19:03:36 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Masami Hiramatsu <mhiramat@...nel.org>,
        Tom Zanussi <zanussi@...nel.org>,
        Keita Suzuki <keitasuzuki.park@...ab.ics.keio.ac.jp>,
        "Steven Rostedt (Google)" <rostedt@...dmis.org>
Subject: [PATCH 5.15 551/667] tracing: Fix potential double free in create_var_ref()

From: Keita Suzuki <keitasuzuki.park@...ab.ics.keio.ac.jp>

commit 99696a2592bca641eb88cc9a80c90e591afebd0f upstream.

In create_var_ref(), init_var_ref() is called to initialize the fields
of variable ref_field, which is allocated in the previous function call
to create_hist_field(). Function init_var_ref() allocates the
corresponding fields such as ref_field->system, but frees these fields
when the function encounters an error. The caller later calls
destroy_hist_field() to conduct error handling, which frees the fields
and the variable itself. This results in double free of the fields which
are already freed in the previous function.

Fix this by storing NULL to the corresponding fields when they are freed
in init_var_ref().

Link: https://lkml.kernel.org/r/20220425063739.3859998-1-keitasuzuki.park@sslab.ics.keio.ac.jp

Fixes: 067fe038e70f ("tracing: Add variable reference handling to hist triggers")
CC: stable@...r.kernel.org
Reviewed-by: Masami Hiramatsu <mhiramat@...nel.org>
Reviewed-by: Tom Zanussi <zanussi@...nel.org>
Signed-off-by: Keita Suzuki <keitasuzuki.park@...ab.ics.keio.ac.jp>
Signed-off-by: Steven Rostedt (Google) <rostedt@...dmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 kernel/trace/trace_events_hist.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1838,8 +1838,11 @@ static int init_var_ref(struct hist_fiel
 	return err;
  free:
 	kfree(ref_field->system);
+	ref_field->system = NULL;
 	kfree(ref_field->event_name);
+	ref_field->event_name = NULL;
 	kfree(ref_field->name);
+	ref_field->name = NULL;
 
 	goto out;
 }