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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EEC10C433F5 for ; Sat, 13 Nov 2021 13:14:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B8EC361077 for ; Sat, 13 Nov 2021 13:14:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235762AbhKMNRA (ORCPT ); Sat, 13 Nov 2021 08:17:00 -0500 Received: from mail.kernel.org ([198.145.29.99]:55900 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231589AbhKMNQ7 (ORCPT ); Sat, 13 Nov 2021 08:16:59 -0500 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 4132660551; Sat, 13 Nov 2021 13:14:07 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.95) (envelope-from ) id 1mlsr7-000Rn5-Py; Sat, 13 Nov 2021 08:14:05 -0500 Message-ID: <20211113131405.640431719@goodmis.org> User-Agent: quilt/0.66 Date: Sat, 13 Nov 2021 08:13:42 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Masami Hiramatsu Subject: [for-linus][PATCH 2/3] tracing/histogram: Do not copy the fixed-size char array field over the field size References: <20211113131340.640683117@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Masami Hiramatsu Do not copy the fixed-size char array field of the events over the field size. The histogram treats char array as a string and there are 2 types of char array in the event, fixed-size and dynamic string. The dynamic string (__data_loc) field must be null terminated, but the fixed-size char array field may not be null terminated (not a string, but just a data). In that case, histogram can copy the data after the field. This uses the original field size for fixed-size char array field to restrict the histogram not to access over the original field size. Link: https://lkml.kernel.org/r/163673292822.195747.3696966210526410250.stgit@devnote2 Fixes: 02205a6752f2 (tracing: Add support for 'field variables') Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_events_hist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 8ff572a31fd3..6a9fa34e2785 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -1953,9 +1953,10 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, if (!hist_field->type) goto free; - if (field->filter_type == FILTER_STATIC_STRING) + if (field->filter_type == FILTER_STATIC_STRING) { hist_field->fn = hist_field_string; - else if (field->filter_type == FILTER_DYN_STRING) + hist_field->size = field->size; + } else if (field->filter_type == FILTER_DYN_STRING) hist_field->fn = hist_field_dynstring; else hist_field->fn = hist_field_pstring; @@ -3025,7 +3026,7 @@ static inline void __update_field_vars(struct tracing_map_elt *elt, char *str = elt_data->field_var_str[j++]; char *val_str = (char *)(uintptr_t)var_val; - strscpy(str, val_str, STR_VAR_LEN_MAX); + strscpy(str, val_str, val->size); var_val = (u64)(uintptr_t)str; } tracing_map_set_var(elt, var_idx, var_val); @@ -4920,7 +4921,7 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data, str = elt_data->field_var_str[idx]; val_str = (char *)(uintptr_t)hist_val; - strscpy(str, val_str, STR_VAR_LEN_MAX); + strscpy(str, val_str, hist_field->size); hist_val = (u64)(uintptr_t)str; } -- 2.33.0