From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS53758 23.128.96.0/24 X-Spam-Status: No, score=-3.7 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by dcvr.yhbt.net (Postfix) with ESMTP id 069271F953 for ; Thu, 16 Dec 2021 17:31:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240236AbhLPRbY (ORCPT ); Thu, 16 Dec 2021 12:31:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60186 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234903AbhLPRbX (ORCPT ); Thu, 16 Dec 2021 12:31:23 -0500 Received: from mail-wr1-x42b.google.com (mail-wr1-x42b.google.com [IPv6:2a00:1450:4864:20::42b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 65A52C061574 for ; Thu, 16 Dec 2021 09:31:23 -0800 (PST) Received: by mail-wr1-x42b.google.com with SMTP id s1so11392075wrg.1 for ; Thu, 16 Dec 2021 09:31:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:from:date:subject:fcc:content-transfer-encoding :mime-version:to:cc; bh=T3CQS4qQo5V/HRec6bFKQcsGe9Xc+vska8JM17oI1x0=; b=VVBWyzY+PF7YL7J/aUkuJvzVm8mq+cmJKO5axKncZv2TNHXevCVFPM7siG/W9SFpm/ u7/X+Lp7GjYEf3PWd1H4+XZeLfd1CppSM25ywRHO+4ZHBFBbjKrJciz7uRurhsz2GIr4 gCApKwjLrVuNV6G+rcJxxIpg9tREq2wzNy/ij/u14DjBntq/OnLW2h5hyUEswMyCbXET 4Vr/xoZ5w6x9lyhw5ZPzVwMvyUuLkzw6iathUCSY0y5bkCKB37f8YR23UCl3PjRRQE56 nBsbXH2IZyrad5tulak924Fv4vNBKW+Oci+CLWm5vw1drFknwhN7Z9D4w0KaGSTPDB4F TB0Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:from:date:subject:fcc :content-transfer-encoding:mime-version:to:cc; bh=T3CQS4qQo5V/HRec6bFKQcsGe9Xc+vska8JM17oI1x0=; b=E3PVxsic4TTuxwxGHqX1uMZg25UIXPlBOlywVcW4R2+iFoJBmBwh8jpUazovmSqXU3 1sCULK374oM6o4t1711fMJaCkWb9FEzWKOCyvebRHnbjhteBY7/+rKU/Otzo9AWGczKh W3VWV2FqSjjB/3JyJ0Z99F/tTQ+Wwc5zaQfeRqoJ12O3izoXBhIVUCzURen/wMqri3Mw VEnqNOGbX2N02JBG5q44A2xath01zXFS4rEjfqUvWj0OQVw4OOv80KbsIuT7ab05HGTi OWO5QVpQkP1QMAZqEAB9I892sF8Oo94LwytptcfIzEW5n+RlAgVsRf7ZV0mcL78BOB8S o8CA== X-Gm-Message-State: AOAM530xMe8xl+/Ouf3B3nuy2gLcrOibB+Atm7d+/+dV4F+PLSkJmdsa phcbs/Xsg8v4TlIzQImb+t5VsiS7+0A= X-Google-Smtp-Source: ABdhPJx/YDGnpyO8ej93j08Gp563P9/T+KTTmKI+TZdW6fRfk17dEcMuhTqWhXJXt4PmDHScpO1rlg== X-Received: by 2002:a5d:5005:: with SMTP id e5mr9956261wrt.700.1639675881810; Thu, 16 Dec 2021 09:31:21 -0800 (PST) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id g16sm6204487wmq.20.2021.12.16.09.31.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 16 Dec 2021 09:31:21 -0800 (PST) Message-Id: From: "Andriy Makukha via GitGitGadget" Date: Thu, 16 Dec 2021 17:31:20 +0000 Subject: [PATCH] strlcpy(): safer and faster version Fcc: Sent Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit MIME-Version: 1.0 To: git@vger.kernel.org Cc: Andriy Makukha , Andrii Makukha Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Andrii Makukha Original strlcpy() has a significant disadvantage of being both unsafe and inefficient. It unnecessarily calculates length of `src` which may result in a segmentation fault if `src` is not terminated with a NUL-character. In this fix, if `src` is too long, strlcpy() returns `size`. This allows to still detect an error while fixing the mentioned vulnerabilities. It deviates from original strlcpy(), but for a good reason. Signed-off-by: Andrii Makukha --- strlcpy(): safer and faster version Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1097%2Famakukha%2Fmaint-v1 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1097/amakukha/maint-v1 Pull-Request: https://github.com/gitgitgadget/git/pull/1097 compat/strlcpy.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/compat/strlcpy.c b/compat/strlcpy.c index 4024c360301..e7fd11015c7 100644 --- a/compat/strlcpy.c +++ b/compat/strlcpy.c @@ -2,7 +2,12 @@ size_t gitstrlcpy(char *dest, const char *src, size_t size) { - size_t ret = strlen(src); + /* + * NOTE: original strlcpy returns full length of src, but this is + * unsafe. This implementation returns `size` if src is too long. + * This behaviour is faster and still allows to detect an issue. + */ + size_t ret = strnlen(src, size); if (size) { size_t len = (ret >= size) ? size - 1 : ret; base-commit: e9d7761bb94f20acc98824275e317fa82436c25d -- gitgitgadget