From patchwork Mon Jun 19 08:19:38 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 13284086 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 0773AEB64DA for ; Mon, 19 Jun 2023 08:20:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230187AbjFSIUc (ORCPT ); Mon, 19 Jun 2023 04:20:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57740 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230180AbjFSIUa (ORCPT ); Mon, 19 Jun 2023 04:20:30 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 818B0FA; Mon, 19 Jun 2023 01:20:27 -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 1ECBD61490; Mon, 19 Jun 2023 08:20:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8663AC433C8; Mon, 19 Jun 2023 08:20:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1687162826; bh=3qmrbX+gre5g324ufIaHDRifEUP5SgH9Kco2mZL155U=; h=From:To:Cc:Subject:Date:From; b=mdMIswmrdfZbEPolQxk4U3MMdRbKG7clRlpwVVU+po7lodeNJWfqP5tlXv7sOyBzk zuKikrud9u1SwwPwOPAY/P0xvVwd5knb/W0+3i7VdRoYukOUV65ZNl5a2qR1iZY19F RxU3Ev3AcFf2V8deVvxspGeIiOKmuRu9tSTIHKiPThxC2Yax0XE8Dqs/lw2XVwohf3 +blK27iRqPof/ng//FKYF95MaC18xx2pYaGreus772awP0FtgxvHQNbrUsAZwK+aLK rBJ8KzE9ezDRoObYV2aghtCwwYI4h9bY2dIH9TE8wToyvEryGZIz6raw1Y0Wv28w63 MQMC0ne7t2ctg== From: Arnd Bergmann To: Namjae Jeon , Steve French Cc: Arnd Bergmann , Sergey Senozhatsky , Tom Talpey , Nathan Chancellor , Nick Desaulniers , Tom Rix , Christian Brauner , Ronnie Sahlberg , Hyunchul Lee , linux-cifs@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH] [v2] smb: avoid field overflow warning Date: Mon, 19 Jun 2023 10:19:38 +0200 Message-Id: <20230619082019.656605-1-arnd@kernel.org> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org From: Arnd Bergmann clang warns about a possible field overflow in a memcpy: In file included from fs/smb/server/smb_common.c:7: include/linux/fortify-string.h:583:4: error: call to '__write_overflow_field' declared with 'warning' attribute: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror,-Wattribute-warning] __write_overflow_field(p_size_field, size); It appears to interpret the "&out[baselen + 4]" as referring to a single byte of the character array, while the equivalen "out + baselen + 4" is seen as an offset into the array. I don't see that kind of warning elsewhere, so just go with the simple rework. Fixes: e2f34481b24db ("cifsd: add server-side procedures for SMB3") Signed-off-by: Arnd Bergmann ---- v2: fix typo in array length, and make sure it still addresses the warning --- fs/smb/server/smb_common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/smb/server/smb_common.c b/fs/smb/server/smb_common.c index a7e81067bc991..39c6c8d7d0623 100644 --- a/fs/smb/server/smb_common.c +++ b/fs/smb/server/smb_common.c @@ -536,7 +536,7 @@ int ksmbd_extract_shortname(struct ksmbd_conn *conn, const char *longname, out[baselen + 3] = PERIOD; if (dot_present) - memcpy(&out[baselen + 4], extension, 4); + memcpy(out + baselen + 4, extension, 4); else out[baselen + 4] = '\0'; smbConvertToUTF16((__le16 *)shortname, out, PATH_MAX,