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 899AFC38142 for ; Sat, 21 Jan 2023 20:37:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229895AbjAUUhP (ORCPT ); Sat, 21 Jan 2023 15:37:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52590 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230006AbjAUUgt (ORCPT ); Sat, 21 Jan 2023 15:36:49 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 14A9329176 for ; Sat, 21 Jan 2023 12:36:45 -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 dfw.source.kernel.org (Postfix) with ESMTPS id A43AA60B92 for ; Sat, 21 Jan 2023 20:36:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6CAE9C433EF for ; Sat, 21 Jan 2023 20:36:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1674333404; bh=VEkoFq9DgQ/t9PgvjnI05sXJeWdbDnvI1z7dx9j6ORI=; h=From:To:Subject:Date:In-Reply-To:References:From; b=QKTyeFqKJTgVz/2ybdDJkBkseGND2s+vADrnwlaxeOWHgPD9nSHGVJO8xCllOakid YhIiPDI2wi5RMCI5N7tC9tfXiLHoj4Io34/bjy+1dxGHWhBxyTPVGFaUl/H0N7SwDi KLjWD5begeqGBXpWj4AqBsgrU0+vd87JPiGHb/LpNNhbasTWT2fTVWHHzEB21ifqP2 yErNCS8ZltB/OnPZk0fY8Y92q5Kp/cF0P6PpG7nUI8uXq4uY7UIh8qKpXSGytaaU58 nSYP5Ce9QpkkV9MQAnY4Cm1Kp1ph1PM9FVnJddp3FJy1XcWdKHCe8SL2vvM+BzBMNQ B5J+is2gez01g== From: Eric Biggers To: linux-ext4@vger.kernel.org Subject: [PATCH 30/38] misc/fuse2fs: avoid error-prone strncpy() pattern Date: Sat, 21 Jan 2023 12:32:22 -0800 Message-Id: <20230121203230.27624-31-ebiggers@kernel.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230121203230.27624-1-ebiggers@kernel.org> References: <20230121203230.27624-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org From: Eric Biggers 'strncpy(dst, src, strlen(src))' is usually wrong, as it doesn't copy the null terminator. For this reason, it causes a -Wstringop-truncation warning with gcc 8 and later. The code happens to be correct anyway, since the destination buffer is zero-initialized. But to avoid relying on this, let's just copy the terminating null. Signed-off-by: Eric Biggers --- misc/fuse2fs.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/misc/fuse2fs.c b/misc/fuse2fs.c index c59572129..6d4bcf4fd 100644 --- a/misc/fuse2fs.c +++ b/misc/fuse2fs.c @@ -2508,9 +2508,10 @@ static int copy_names(char *name, char *value EXT2FS_ATTR((unused)), size_t value_len EXT2FS_ATTR((unused)), void *data) { char **b = data; + size_t name_len = strlen(name); - strncpy(*b, name, strlen(name)); - *b = *b + strlen(name) + 1; + memcpy(*b, name, name_len + 1); + *b = *b + name_len + 1; return 0; } -- 2.39.0