From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BBFCDC433FE for ; Wed, 23 Nov 2022 09:17:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237371AbiKWJRW (ORCPT ); Wed, 23 Nov 2022 04:17:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58548 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237420AbiKWJQy (ORCPT ); Wed, 23 Nov 2022 04:16:54 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C68A5108937 for ; Wed, 23 Nov 2022 01:16:23 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id B220CCE20EC for ; Wed, 23 Nov 2022 09:16:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6F3F9C433C1; Wed, 23 Nov 2022 09:16:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1669194979; bh=YAx0O8hu4W+XO3DC1SvBaGe0aeZ1TmlGsoJNDEZiJNs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MwdG3pZnPNQNVBo1W+9tJxOM6xD+8aHNqcKqTwa7GsR2e9Z4k8nX9pzalb4kD239I umI+lo1Xz8nvp3Dlq0UTm8sB6QdYffwvfZ4GzIbJWVuSup9UX9yWsCkqEvvvR17DWO CpLrQ96oBQpchLEmfHPFcOcuwRS74N5qdfjz8/g0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xiu Jianfeng , "Steven Rostedt (Google)" Subject: [PATCH 5.4 113/156] ftrace: Fix null pointer dereference in ftrace_add_mod() Date: Wed, 23 Nov 2022 09:51:10 +0100 Message-Id: <20221123084602.044152049@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221123084557.816085212@linuxfoundation.org> References: <20221123084557.816085212@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Xiu Jianfeng commit 19ba6c8af9382c4c05dc6a0a79af3013b9a35cd0 upstream. The @ftrace_mod is allocated by kzalloc(), so both the members {prev,next} of @ftrace_mode->list are NULL, it's not a valid state to call list_del(). If kstrdup() for @ftrace_mod->{func|module} fails, it goes to @out_free tag and calls free_ftrace_mod() to destroy @ftrace_mod, then list_del() will write prev->next and next->prev, where null pointer dereference happens. BUG: kernel NULL pointer dereference, address: 0000000000000008 Oops: 0002 [#1] PREEMPT SMP NOPTI Call Trace: ftrace_mod_callback+0x20d/0x220 ? do_filp_open+0xd9/0x140 ftrace_process_regex.isra.51+0xbf/0x130 ftrace_regex_write.isra.52.part.53+0x6e/0x90 vfs_write+0xee/0x3a0 ? __audit_filter_op+0xb1/0x100 ? auditd_test_task+0x38/0x50 ksys_write+0xa5/0xe0 do_syscall_64+0x3a/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Kernel panic - not syncing: Fatal exception So call INIT_LIST_HEAD() to initialize the list member to fix this issue. Link: https://lkml.kernel.org/r/20221116015207.30858-1-xiujianfeng@huawei.com Cc: stable@vger.kernel.org Fixes: 673feb9d76ab ("ftrace: Add :mod: caching infrastructure to trace_array") Signed-off-by: Xiu Jianfeng Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/ftrace.c | 1 + 1 file changed, 1 insertion(+) --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1307,6 +1307,7 @@ static int ftrace_add_mod(struct trace_a if (!ftrace_mod) return -ENOMEM; + INIT_LIST_HEAD(&ftrace_mod->list); ftrace_mod->func = kstrdup(func, GFP_KERNEL); ftrace_mod->module = kstrdup(module, GFP_KERNEL); ftrace_mod->enable = enable;