From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BB15A30FA5 for ; Wed, 20 Sep 2023 12:17:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 37CC3C433AB; Wed, 20 Sep 2023 12:17:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1695212255; bh=7hJ5yK9X51tnUCh3ItGKKsZ0kaguA29sI6Fxn2R70Lc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cAr66AwGFmwqY4jHbnY2Onz9BMZKjB4Vs9J/Yy1HaMBOo+ZeBkpN/Z0Bs50mOr3+v +zjRCXDZCUU12z+Vh2TZgMjY6g8XJoNGAItXGeIpwpu1V7yI6j0W44iBxrUAZYuvnC lNt88RUR/y04G3D7yIO7qdZk5dLVbZ5FA+lctDMk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Wander Lairson Costa , Pablo Neira Ayuso Subject: [PATCH 4.19 167/273] netfilter: xt_u32: validate user space input Date: Wed, 20 Sep 2023 13:30:07 +0200 Message-ID: <20230920112851.683360050@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230920112846.440597133@linuxfoundation.org> References: <20230920112846.440597133@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wander Lairson Costa commit 69c5d284f67089b4750d28ff6ac6f52ec224b330 upstream. The xt_u32 module doesn't validate the fields in the xt_u32 structure. An attacker may take advantage of this to trigger an OOB read by setting the size fields with a value beyond the arrays boundaries. Add a checkentry function to validate the structure. This was originally reported by the ZDI project (ZDI-CAN-18408). Fixes: 1b50b8a371e9 ("[NETFILTER]: Add u32 match") Cc: stable@vger.kernel.org Signed-off-by: Wander Lairson Costa Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman --- net/netfilter/xt_u32.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) --- a/net/netfilter/xt_u32.c +++ b/net/netfilter/xt_u32.c @@ -95,11 +95,32 @@ static bool u32_mt(const struct sk_buff return ret ^ data->invert; } +static int u32_mt_checkentry(const struct xt_mtchk_param *par) +{ + const struct xt_u32 *data = par->matchinfo; + const struct xt_u32_test *ct; + unsigned int i; + + if (data->ntests > ARRAY_SIZE(data->tests)) + return -EINVAL; + + for (i = 0; i < data->ntests; ++i) { + ct = &data->tests[i]; + + if (ct->nnums > ARRAY_SIZE(ct->location) || + ct->nvalues > ARRAY_SIZE(ct->value)) + return -EINVAL; + } + + return 0; +} + static struct xt_match xt_u32_mt_reg __read_mostly = { .name = "u32", .revision = 0, .family = NFPROTO_UNSPEC, .match = u32_mt, + .checkentry = u32_mt_checkentry, .matchsize = sizeof(struct xt_u32), .me = THIS_MODULE, };