From patchwork Wed Jul 3 06:20:14 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nitin Gote X-Patchwork-Id: 11028933 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 89FFE14F6 for ; Wed, 3 Jul 2019 06:20:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 79B43282E8 for ; Wed, 3 Jul 2019 06:20:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 68B6C2807B; Wed, 3 Jul 2019 06:20:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id D36662807B for ; Wed, 3 Jul 2019 06:20:56 +0000 (UTC) Received: (qmail 23602 invoked by uid 550); 3 Jul 2019 06:20:54 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 23561 invoked from network); 3 Jul 2019 06:20:54 -0000 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,446,1557212400"; d="scan'208";a="172025329" From: Nitin Gote To: keescook@chromium.org Cc: jannh@google.com, kernel-hardening@lists.openwall.com, Nitin Gote Subject: [PATCH v2] checkpatch: Added warnings in favor of strscpy(). Date: Wed, 3 Jul 2019 11:50:14 +0530 Message-Id: <1562134814-12966-1-git-send-email-nitin.r.gote@intel.com> X-Mailer: git-send-email 2.7.4 X-Virus-Scanned: ClamAV using ClamSMTP Added warnings in checkpatch.pl script to : 1. Deprecate strcpy() in favor of strscpy(). 2. Deprecate strlcpy() in favor of strscpy(). 3. Deprecate strncpy() in favor of strscpy() or strscpy_pad(). Updated strncpy() section in Documentation/process/deprecated.rst to cover strscpy_pad() case. Signed-off-by: Nitin Gote Acked-by: Kees Cook --- Documentation/process/deprecated.rst | 6 +++--- scripts/checkpatch.pl | 4 ++++ 2 files changed, 7 insertions(+), 3 deletions(-) -- 2.7.4 diff --git a/Documentation/process/deprecated.rst b/Documentation/process/deprecated.rst index 49e0f64..f564de3 100644 --- a/Documentation/process/deprecated.rst +++ b/Documentation/process/deprecated.rst @@ -93,9 +93,9 @@ will be NUL terminated. This can lead to various linear read overflows and other misbehavior due to the missing termination. It also NUL-pads the destination buffer if the source contents are shorter than the destination buffer size, which may be a needless performance penalty for callers using -only NUL-terminated strings. The safe replacement is :c:func:`strscpy`. -(Users of :c:func:`strscpy` still needing NUL-padding will need an -explicit :c:func:`memset` added.) +only NUL-terminated strings. In this case, the safe replacement is +:c:func:`strscpy`. If, however, the destination buffer still needs +NUL-padding, the safe replacement is :c:func:`strscpy_pad`. If a caller is using non-NUL-terminated strings, :c:func:`strncpy()` can still be used, but destinations should be marked with the `__nonstring diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 342c7c7..2ce2340 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -595,6 +595,10 @@ our %deprecated_apis = ( "rcu_barrier_sched" => "rcu_barrier", "get_state_synchronize_sched" => "get_state_synchronize_rcu", "cond_synchronize_sched" => "cond_synchronize_rcu", + "strcpy" => "strscpy", + "strlcpy" => "strscpy", + "strncpy" => "strscpy, strscpy_pad or for non-NUL-terminated strings, + strncpy() can still be used, but destinations should be marked with the __nonstring", ); #Create a search pattern for all these strings to speed up a loop below