From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Nicolas Pitre To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Alexander Viro , David Howells , Greg Ungerer Subject: [PATCH v3 03/12] binfmt_flat: prevent kernel dammage from corrupted executable headers Date: Wed, 20 Jul 2016 00:20:15 -0400 Message-Id: <1468988424-32671-4-git-send-email-nicolas.pitre@linaro.org> In-Reply-To: <1468988424-32671-1-git-send-email-nicolas.pitre@linaro.org> References: <1468988424-32671-1-git-send-email-nicolas.pitre@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: Signed-off-by: Nicolas Pitre --- fs/binfmt_flat.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c index 36f5bb6b2c..9c76d9a222 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -470,6 +470,17 @@ static int load_flat_file(struct linux_binprm * bprm, } /* + * Make sure the header params are sane. + * 28 bits (256 MB) is way more than reasonable in this case. + * If some top bits are set we have probable binary corruption. + */ + if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) { + pr_err("bad header\n"); + ret = -ENOEXEC; + goto err; + } + + /* * fix up the flags for the older format, there were all kinds * of endian hacks, this only works for the simple cases */ -- 2.7.4