From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 595633B7B98; Tue, 21 Jul 2026 20:48:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784666883; cv=none; b=WZae0SzKBc3frqm6op/aOui1NHCdzLBMMyKN0MGgTWSFeS+0RNmk2hf76vmReEAZTLpfnBhFCu5GZQb1NIELlupFu15L9kMJ+ZfHKzIJ8pLzR0KDA6oQRh8ArKtPextvqJdsKY0kdKEqcJPSwu9QJYpSR929alFcI/63D7UTzBU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784666883; c=relaxed/simple; bh=nLzw4Ic8c3O5i6l3WMDtk4FEakDNVx0tgu3UTxdRmiA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XtIoh0kSyz2j4cd4sm/fHt6ld8fogxEdjXvvCpJboXikWWx+m8sigeEKo96UJyIcx+fRsTKMmnbSCbKw8CW67Q5A/mNE72nVTx4JLlFxHU132OQgmuseJofP+rRW41qPU6xp5D12Rt1JFTrSQ/jdc9PHbAGDxRoQ2lVt/UFpfR4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=MxW1GRGj; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="MxW1GRGj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 342CB1F00A3D; Tue, 21 Jul 2026 20:47:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784666879; bh=bIHtGK48kSkhD9fB6ALVVpVVHFfh/229OZcxU2//cFM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=MxW1GRGjZZ7bPaC3ch6Dbq3XuMl/x6ry1fWor9qD4ZUFQTSbRPiRvVmjdld0P7013 q6msSfo7/54oD++M4CCjAQILhBIMRk+0Gxfid7EY2tFR/HyLLzqsKO7p+YFXvqB3j3 jLr1sGXeLjNFDch0otihjGxmQXxxlYSdPFXe+eDg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yuan Tan , Yifan Wu , Juefei Pu , Zhengchuan Liang , Xin Liu , Wyatt Feng , Ren Wei , Florian Westphal , Sasha Levin Subject: [PATCH 6.6 0850/1266] netfilter: xt_u32: reject invalid shift counts Date: Tue, 21 Jul 2026 17:21:27 +0200 Message-ID: <20260721152500.876129501@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152441.786066624@linuxfoundation.org> References: <20260721152441.786066624@linuxfoundation.org> User-Agent: quilt/0.69 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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wyatt Feng [ Upstream commit 64cdf7d30ac18e43df6c48004435febb965809a8 ] u32_match_it() executes rule-supplied shift operands on a 32-bit value. A malformed u32 rule can provide a shift count of 32 or more, triggering an undefined shift out-of-bounds during packet evaluation. Validate XT_U32_LEFTSH and XT_U32_RIGHTSH operands in u32_mt_checkentry() and reject malformed rules before they reach the packet path. Fixes: 1b50b8a371e9 ("[NETFILTER]: Add u32 match") Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Zhengchuan Liang Reported-by: Xin Liu Assisted-by: Codex:GPT-5.4 Signed-off-by: Wyatt Feng Signed-off-by: Ren Wei Signed-off-by: Florian Westphal Signed-off-by: Sasha Levin --- net/netfilter/xt_u32.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/net/netfilter/xt_u32.c b/net/netfilter/xt_u32.c index 117d4615d6684c..ec1a21e3b6e2c3 100644 --- a/net/netfilter/xt_u32.c +++ b/net/netfilter/xt_u32.c @@ -100,7 +100,7 @@ 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; + unsigned int i, j; if (data->ntests > ARRAY_SIZE(data->tests)) return -EINVAL; @@ -111,6 +111,16 @@ static int u32_mt_checkentry(const struct xt_mtchk_param *par) if (ct->nnums > ARRAY_SIZE(ct->location) || ct->nvalues > ARRAY_SIZE(ct->value)) return -EINVAL; + + for (j = 1; j < ct->nnums; ++j) { + switch (ct->location[j].nextop) { + case XT_U32_LEFTSH: + case XT_U32_RIGHTSH: + if (ct->location[j].number >= 32) + return -EINVAL; + break; + } + } } return 0; -- 2.53.0