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 EA62BC0015E for ; Fri, 21 Jul 2023 18:50:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229452AbjGUSuL (ORCPT ); Fri, 21 Jul 2023 14:50:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44480 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229785AbjGUSuL (ORCPT ); Fri, 21 Jul 2023 14:50:11 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 311B230DB for ; Fri, 21 Jul 2023 11:50:10 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id AF0A061D7E for ; Fri, 21 Jul 2023 18:50:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C05DFC433C9; Fri, 21 Jul 2023 18:50:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689965409; bh=Hdo6DbvAgmMU4xuvtIgRyRNRhcbVjoBzjcw0Y96QtyY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hZasBNBVyWRY2GxtI86Vuuqi6XEfMN8r5jTMzA4EiM1AVBBpJrGOClpCDroOKrj25 6xy5Mpgxv5efMIC3/3MPrvB1AZVafv1uwtlLhdOlWwf5/i69il88/3iOAWAITlJw8v oJgtnVuXVZHEG4EbPG3jXFzg/dUUZqcaOgUXBhf0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Steven Rostedt (Google)" , "Masami Hiramatsu (Google)" Subject: [PATCH 6.4 273/292] tracing/probes: Fix to record 0-length data_loc in fetch_store_string*() if fails Date: Fri, 21 Jul 2023 18:06:22 +0200 Message-ID: <20230721160540.665231997@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230721160528.800311148@linuxfoundation.org> References: <20230721160528.800311148@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: Masami Hiramatsu (Google) commit 797311bce5c2ac90b8d65e357603cfd410d36ebb upstream. Fix to record 0-length data to data_loc in fetch_store_string*() if it fails to get the string data. Currently those expect that the data_loc is updated by store_trace_args() if it returns the error code. However, that does not work correctly if the argument is an array of strings. In that case, store_trace_args() only clears the first entry of the array (which may have no error) and leaves other entries. So it should be cleared by fetch_store_string*() itself. Also, 'dyndata' and 'maxlen' in store_trace_args() should be updated only if it is used (ret > 0 and argument is a dynamic data.) Link: https://lore.kernel.org/all/168908496683.123124.4761206188794205601.stgit@devnote2/ Fixes: 40b53b771806 ("tracing: probeevent: Add array type support") Cc: stable@vger.kernel.org Reviewed-by: Steven Rostedt (Google) Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace_probe_kernel.h | 13 +++++++++---- kernel/trace/trace_probe_tmpl.h | 10 +++------- kernel/trace/trace_uprobe.c | 3 ++- 3 files changed, 14 insertions(+), 12 deletions(-) --- a/kernel/trace/trace_probe_kernel.h +++ b/kernel/trace/trace_probe_kernel.h @@ -37,6 +37,13 @@ fetch_store_strlen(unsigned long addr) return (ret < 0) ? ret : len; } +static nokprobe_inline void set_data_loc(int ret, void *dest, void *__dest, void *base) +{ + if (ret < 0) + ret = 0; + *(u32 *)dest = make_data_loc(ret, __dest - base); +} + /* * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf * with max length and relative data location. @@ -55,8 +62,7 @@ fetch_store_string_user(unsigned long ad __dest = get_loc_data(dest, base); ret = strncpy_from_user_nofault(__dest, uaddr, maxlen); - if (ret >= 0) - *(u32 *)dest = make_data_loc(ret, __dest - base); + set_data_loc(ret, dest, __dest, base); return ret; } @@ -87,8 +93,7 @@ fetch_store_string(unsigned long addr, v * probing. */ ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen); - if (ret >= 0) - *(u32 *)dest = make_data_loc(ret, __dest - base); + set_data_loc(ret, dest, __dest, base); return ret; } --- a/kernel/trace/trace_probe_tmpl.h +++ b/kernel/trace/trace_probe_tmpl.h @@ -267,13 +267,9 @@ store_trace_args(void *data, struct trac if (unlikely(arg->dynamic)) *dl = make_data_loc(maxlen, dyndata - base); ret = process_fetch_insn(arg->code, rec, dl, base); - if (arg->dynamic) { - if (unlikely(ret < 0)) { - *dl = make_data_loc(0, dyndata - base); - } else { - dyndata += ret; - maxlen -= ret; - } + if (arg->dynamic && likely(ret > 0)) { + dyndata += ret; + maxlen -= ret; } } } --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -170,7 +170,8 @@ fetch_store_string(unsigned long addr, v */ ret++; *(u32 *)dest = make_data_loc(ret, (void *)dst - base); - } + } else + *(u32 *)dest = make_data_loc(0, (void *)dst - base); return ret; }