From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?q?Erik=20Elfstr=C3=B6m?= Subject: [PATCH v8 2/5] setup: sanity check file size in read_gitfile_gently Date: Mon, 15 Jun 2015 21:39:52 +0200 Message-ID: <1434397195-1823-3-git-send-email-erik.elfstrom@gmail.com> References: <1434397195-1823-1-git-send-email-erik.elfstrom@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: =?UTF-8?q?Erik=20Elfstr=C3=B6m?= To: git@vger.kernel.org X-From: git-owner@vger.kernel.org Mon Jun 15 21:40:39 2015 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Z4aFJ-00045T-26 for gcvg-git-2@plane.gmane.org; Mon, 15 Jun 2015 21:40:37 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756009AbbFOTkd convert rfc822-to-quoted-printable (ORCPT ); Mon, 15 Jun 2015 15:40:33 -0400 Received: from mail-la0-f42.google.com ([209.85.215.42]:35209 "EHLO mail-la0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754117AbbFOTkb (ORCPT ); Mon, 15 Jun 2015 15:40:31 -0400 Received: by labko7 with SMTP id ko7so64830832lab.2 for ; Mon, 15 Jun 2015 12:40:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-type:content-transfer-encoding; bh=iyUuUV5CYr4yUV6a8KJIABtYgxj3e+PBSaWzY36bPdM=; b=eclGYExM7Xfd1WwBHwixRV2dgxlsrKFNr4e/IEFVvnyVxPULeNfzRExsvnZl9G4jVo CbxJTiFN6lcaTaEIoB5GiAuJjwd+pTdGClTNs2HSPQZgEYbWB+bj/aKOaofUZ7dtVchJ veLggLofftbhs78q6rI4Ohsmuj6E39P+fG4WQjPBcJXJIjsHjugUI+BbU0IsljRS/X/g wblqIjI7hLpBDUGYfChanM7n/NGL+eRqlblMYSnsCz1+joIvsMlLHCi6fmEoTS/wgnin vk1YlNfO2Zn7a1AZUgyVy0OHBw6+QxJjkrO0IpzKrbz+9CXj2qBlkDsuBOth4RL33ThO zuXw== X-Received: by 10.112.126.42 with SMTP id mv10mr1773162lbb.58.1434397230182; Mon, 15 Jun 2015 12:40:30 -0700 (PDT) Received: from localhost.localdomain (h38n2-lk-d2.ias.bredband.telia.com. [78.72.191.38]) by mx.google.com with ESMTPSA id a7sm2923526lbc.36.2015.06.15.12.40.28 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 15 Jun 2015 12:40:29 -0700 (PDT) X-Mailer: git-send-email 2.4.3.373.gc496bfb.dirty In-Reply-To: <1434397195-1823-1-git-send-email-erik.elfstrom@gmail.com> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: read_gitfile_gently will allocate a buffer to fit the entire file that should be read. Add a sanity check of the file size before opening to avoid allocating a potentially huge amount of memory if we come across a large file that someone happened to name ".git". The limit is set to a sufficiently unreasonable size that should never be exceeded by a genuine .git file. Signed-off-by: Erik Elfstr=C3=B6m --- cache.h | 1 + setup.c | 7 +++++++ 2 files changed, 8 insertions(+) diff --git a/cache.h b/cache.h index 25578cb..858d9b3 100644 --- a/cache.h +++ b/cache.h @@ -454,6 +454,7 @@ extern const char *get_git_work_tree(void); #define READ_GITFILE_ERR_INVALID_FORMAT 5 #define READ_GITFILE_ERR_NO_PATH 6 #define READ_GITFILE_ERR_NOT_A_REPO 7 +#define READ_GITFILE_ERR_TOO_LARGE 8 extern const char *read_gitfile_gently(const char *path, int *return_e= rror_code); #define read_gitfile(path) read_gitfile_gently((path), NULL) extern const char *resolve_gitdir(const char *suspect); diff --git a/setup.c b/setup.c index 4748b63..a03ca94 100644 --- a/setup.c +++ b/setup.c @@ -414,6 +414,7 @@ static void update_linked_gitdir(const char *gitfil= e, const char *gitdir) */ const char *read_gitfile_gently(const char *path, int *return_error_co= de) { + const int max_file_size =3D 1 << 20; /* 1MB */ int error_code =3D 0; char *buf =3D NULL; char *dir =3D NULL; @@ -430,6 +431,10 @@ const char *read_gitfile_gently(const char *path, = int *return_error_code) error_code =3D READ_GITFILE_ERR_NOT_A_FILE; goto cleanup_return; } + if (st.st_size > max_file_size) { + error_code =3D READ_GITFILE_ERR_TOO_LARGE; + goto cleanup_return; + } fd =3D open(path, O_RDONLY); if (fd < 0) { error_code =3D READ_GITFILE_ERR_OPEN_FAILED; @@ -489,6 +494,8 @@ cleanup_return: return NULL; case READ_GITFILE_ERR_OPEN_FAILED: die_errno("Error opening '%s'", path); + case READ_GITFILE_ERR_TOO_LARGE: + die("Too large to be a .git file: '%s'", path); case READ_GITFILE_ERR_READ_FAILED: die("Error reading %s", path); case READ_GITFILE_ERR_INVALID_FORMAT: --=20 2.4.3.373.gc496bfb.dirty