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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD098C54FD0 for ; Thu, 23 Apr 2020 23:19:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7CC521556 for ; Thu, 23 Apr 2020 23:19:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729846AbgDWXTg (ORCPT ); Thu, 23 Apr 2020 19:19:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:55702 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729802AbgDWXTV (ORCPT ); Thu, 23 Apr 2020 19:19:21 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 537B520CC7; Thu, 23 Apr 2020 23:19:21 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.93) (envelope-from ) id 1jRl7o-000Yri-7L; Thu, 23 Apr 2020 19:19:20 -0400 Message-Id: <20200423231920.111437253@goodmis.org> User-Agent: quilt/0.65 Date: Thu, 23 Apr 2020 19:18:39 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Vamshi K Sthambamkadi Subject: [for-linus][PATCH 1/4] tracing: Fix memory leaks in trace_events_hist.c References: <20200423231838.682478056@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vamshi K Sthambamkadi kmemleak report 1: [<9092c50b>] kmem_cache_alloc_trace+0x138/0x270 [<05a2c9ed>] create_field_var+0xcf/0x180 [<528a2d68>] action_create+0xe2/0xc80 [<63f50b61>] event_hist_trigger_func+0x15b5/0x1920 [<28ea5d3d>] trigger_process_regex+0x7b/0xc0 [<3138e86f>] event_trigger_write+0x4d/0xb0 [] __vfs_write+0x30/0x200 [<4f424a0d>] vfs_write+0x96/0x1b0 [] ksys_write+0x53/0xc0 [<3717101a>] __ia32_sys_write+0x15/0x20 [] do_fast_syscall_32+0x70/0x250 [<46e2629c>] entry_SYSENTER_32+0xaf/0x102 This is because save_vars[] of struct hist_trigger_data are not destroyed kmemleak report 2: [<9092c50b>] kmem_cache_alloc_trace+0x138/0x270 [<6e5e97c5>] create_var+0x3c/0x110 [] create_field_var+0xaf/0x180 [<528a2d68>] action_create+0xe2/0xc80 [<63f50b61>] event_hist_trigger_func+0x15b5/0x1920 [<28ea5d3d>] trigger_process_regex+0x7b/0xc0 [<3138e86f>] event_trigger_write+0x4d/0xb0 [] __vfs_write+0x30/0x200 [<4f424a0d>] vfs_write+0x96/0x1b0 [] ksys_write+0x53/0xc0 [<3717101a>] __ia32_sys_write+0x15/0x20 [] do_fast_syscall_32+0x70/0x250 [<46e2629c>] entry_SYSENTER_32+0xaf/0x102 struct hist_field allocated through create_var() do not initialize "ref" field to 1. The code in __destroy_hist_field() does not destroy object if "ref" is initialized to zero, the condition if (--hist_field->ref > 1) always passes since unsigned int wraps. kmemleak report 3: [] __kmalloc_track_caller+0x139/0x2b0 [] kstrdup+0x27/0x50 [<39d70006>] init_var_ref+0x58/0xd0 [<8ca76370>] create_var_ref+0x89/0xe0 [] action_create+0x38f/0xc80 [<7c146821>] event_hist_trigger_func+0x15b5/0x1920 [<07de3f61>] trigger_process_regex+0x7b/0xc0 [] event_trigger_write+0x4d/0xb0 [<19bf1512>] __vfs_write+0x30/0x200 [<64ce4d27>] vfs_write+0x96/0x1b0 [] ksys_write+0x53/0xc0 [<7d4230cd>] __ia32_sys_write+0x15/0x20 [<8eadca00>] do_fast_syscall_32+0x70/0x250 [<235cf985>] entry_SYSENTER_32+0xaf/0x102 hist_fields (system & event_name) are not freed Link: http://lkml.kernel.org/r/20200422061503.GA5151@cosmos Signed-off-by: Vamshi K Sthambamkadi Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_events_hist.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 5f6834a2bf41..fcab11cc6833 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -3320,6 +3320,9 @@ static void __destroy_hist_field(struct hist_field *hist_field) kfree(hist_field->name); kfree(hist_field->type); + kfree(hist_field->system); + kfree(hist_field->event_name); + kfree(hist_field); } @@ -4382,6 +4385,7 @@ static struct hist_field *create_var(struct hist_trigger_data *hist_data, goto out; } + var->ref = 1; var->flags = HIST_FIELD_FL_VAR; var->var.idx = idx; var->var.hist_data = var->hist_data = hist_data; @@ -5011,6 +5015,9 @@ static void destroy_field_vars(struct hist_trigger_data *hist_data) for (i = 0; i < hist_data->n_field_vars; i++) destroy_field_var(hist_data->field_vars[i]); + + for (i = 0; i < hist_data->n_save_vars; i++) + destroy_field_var(hist_data->save_vars[i]); } static void save_field_var(struct hist_trigger_data *hist_data, -- 2.26.1