From patchwork Mon Jul 3 18:05:28 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Azeem Shaikh X-Patchwork-Id: 13300332 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 EF22AC001B0 for ; Mon, 3 Jul 2023 18:05:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229960AbjGCSFm (ORCPT ); Mon, 3 Jul 2023 14:05:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34126 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229763AbjGCSFl (ORCPT ); Mon, 3 Jul 2023 14:05:41 -0400 Received: from mail-il1-x12c.google.com (mail-il1-x12c.google.com [IPv6:2607:f8b0:4864:20::12c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A5B84B3; Mon, 3 Jul 2023 11:05:40 -0700 (PDT) Received: by mail-il1-x12c.google.com with SMTP id e9e14a558f8ab-345a76c3a2eso19728145ab.2; Mon, 03 Jul 2023 11:05:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1688407540; x=1690999540; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=xc58Ur2dGlcRpxmurRMRf+D6DXpC7t63Ku8gr49XadE=; b=f4wKtFMUv6J14dYTXrMSx0k6E7jglxt1xK14WAUWV0b766oNc+aKi21PdDxpQyIdTC XQfOAupMbERsYSknauHVLAiX/TL2AvSrVaBVhbahw1zF2Rzbqt1xyAUe4D+eBzSzzBsg a2QrwJhpHUnezr1uheh08eT5Q0rEBk7fVNW2VMeUIqPPfQdNUd4rUvfJBzR60zTnvhX+ BsawhnL9a/3RudGMp4bM9bjibdQKHTTjdrbIEaKoxTcdw9PYQtvdrkeQIfQUAzIvw4tp yTIoRC5EUgwO9jERqZrPG2gXH7cDgkiMu4v9fsWBHxs6C+NK0nEXF5Az5ibbTMcV9Ppy DYHA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1688407540; x=1690999540; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=xc58Ur2dGlcRpxmurRMRf+D6DXpC7t63Ku8gr49XadE=; b=ZKLfD0hAqASVnTdmNV2B63B+BlfK3WCSdOiMSeXvBrkp6U7x54Q0cKD5a6z8obl/Pp 4wS/VFmvB5lyIVGw4M8KKr25+y1wl855oiPIC232zdM0R6A0nX+x17aqto5O6Ko26USz c1SpJcpRcnQEriZALZXogrQRkwF9DJne9UofgnOykt02WIoxdBQFY9sS2+BRuUdO9OcS PkBj40ZwNlsWI6mhAiKI3h0fvvzJHhP4ZfpQPo6ElMVbxP8AnLJwPFWiTrXxikquQa2E vi54t2f5egADPfLQijXTG6/dlq7x0YH2YEhmhsqR8AKf47m7IOtBC+oIqeNWXN+K14PG z6Ag== X-Gm-Message-State: ABy/qLY5MpxDbmVF6XtZaXkqHWsOQnzPgI05JPInKjM8l3jzN9QU7fmn h3ihIZ3erbpady5ADDerJfXF9Rsolr2HsizB X-Google-Smtp-Source: APBJJlG26HFbuy6WLJJH3/OP3LWrbSl1RRU6w5AVIoR4xY3vw00eAhSCy/nKt20FFKarLU2DB9SjqQ== X-Received: by 2002:a92:d9d0:0:b0:345:aee1:eaeb with SMTP id n16-20020a92d9d0000000b00345aee1eaebmr9743039ilq.11.1688407539649; Mon, 03 Jul 2023 11:05:39 -0700 (PDT) Received: from azeems-kspp.c.googlers.com.com (54.70.188.35.bc.googleusercontent.com. [35.188.70.54]) by smtp.gmail.com with ESMTPSA id u16-20020a02c050000000b0042b35c7b8c5sm1419054jam.61.2023.07.03.11.05.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 03 Jul 2023 11:05:39 -0700 (PDT) From: Azeem Shaikh To: Greg Kroah-Hartman Cc: linux-hardening@vger.kernel.org, Azeem Shaikh , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org Subject: [PATCH] kobject: Replace strlcpy with strscpy Date: Mon, 3 Jul 2023 18:05:28 +0000 Message-ID: <20230703180528.3709258-1-azeemshaikh38@gmail.com> X-Mailer: git-send-email 2.41.0.255.g8b1d071c50-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. In an effort to remove strlcpy() completely [2], replace strlcpy() here with strscpy(). Direct replacement is safe here since return value of -errno is used to check for truncation instead of sizeof(dest). [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Signed-off-by: Azeem Shaikh --- lib/kobject_uevent.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index 7c44b7ae4c5c..e5497fa0a2d2 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -254,8 +254,8 @@ static int init_uevent_argv(struct kobj_uevent_env *env, const char *subsystem) int buffer_size = sizeof(env->buf) - env->buflen; int len; - len = strlcpy(&env->buf[env->buflen], subsystem, buffer_size); - if (len >= buffer_size) { + len = strscpy(&env->buf[env->buflen], subsystem, buffer_size); + if (len < 0) { pr_warn("init_uevent_argv: buffer size of %d too small, needed %d\n", buffer_size, len); return -ENOMEM;