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 2158F3644B3; Tue, 21 Jul 2026 19:47:54 +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=1784663275; cv=none; b=WWzEc4TgX2TlLFFuISIYihnIxLjuCa50uAxNwDDCb31i2uTk/03tuo48vmNq2yEktFSczpZpkE1k0YnhmQYbxQTv5RnX0BDajUPspPSFLRRiJg5//QqlEyfGi4RL4Kwn4wkdEnbcu2f+rdSFfaa/omrTFXoj8ibnvqpDSQ0XzIw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784663275; c=relaxed/simple; bh=EWaQLKoIVa8RhzlK1lZKvkRWwxUdzwWmIAZQS6FcE24=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eOLyD38RcvrLwFQv3OL/ImjQi6Lo/C/TiVQk/B6b/hMAoAdoJtNF3s+Gqk+3vGDoouG42z6HOvYul4Qr35ioLTZTcCfsxHSQrlQlOQNhtSvOm7qlUoMBbcYKsWkbGNH1GonzIUJxQ3e6gly4KSbzkENvsPBzIQcJZPwegy4EymY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ebw9M42W; 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="ebw9M42W" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8FA851F000E9; Tue, 21 Jul 2026 19:47:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784663274; bh=KXxAoefucgZz9ASzpsf8YhDZbXQ6jiCgtOujdmBroJU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ebw9M42WJrUwUQEIR/9PSqMt7wWDM0bgZylAtDiBRsD+6OuslUOBRKjgUM/BXmg3+ jy0//1UzDM5P1g7kZQGd+G88d4bJh7id0ppMsnsxGbf9YqwyfdZUWuEQ9DPIGuEwa2 +ZD/9TDN6Icytb3bVfT+X522EuhYpO8Z1nJEYYF8= 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 6.12 0761/1276] netfilter: xt_u32: reject invalid shift counts Date: Tue, 21 Jul 2026 17:20:04 +0200 Message-ID: <20260721152503.106648753@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152446.065700225@linuxfoundation.org> References: <20260721152446.065700225@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 6.12-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 1ae7f926b0df73..dabbaa742874cb 100644 --- a/net/netfilter/xt_u32.c +++ b/net/netfilter/xt_u32.c @@ -106,7 +106,7 @@ 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; @@ -117,6 +117,16 @@ 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