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 6BE9147141E; Tue, 21 Jul 2026 22:15:58 +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=1784672159; cv=none; b=L4OiuwaazZvHSw6xk2K3a7J30UHtlry9H8GJkrf1+ePbzpMPDh7pTFfj6r71wr5GPslts+pfK1HSmJJSerplENNqhvynw42Ru57CVnKqSUlLkkignlQa0LD6gg9F5lBaVs1omZoL0lUNILVcR7UsjXY79N8mWB2zgwyeaF9ZS/A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784672159; c=relaxed/simple; bh=liYwuMHDeWu++VWyrtcZxF5RuIAzBBjFGhMErt7WRJQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bkB6ATS6Ar3F1p+xVKuYzJOxXOAOG6DTKgQ2pS66GV5vg2pyIpLUlSF1lj8NzhN/y1lfToPWakUHRND9aAWFCKMPl2mIwHwmBgYE2gg2pNHDqv/UZnaxjP1+zhNvIlN/4aoEfpfbrItgjeJBOfZdpFAglcwFwZqMpZbL08Pg7w4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=KH+8KyJt; 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="KH+8KyJt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A6DC91F000E9; Tue, 21 Jul 2026 22:15:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784672158; bh=8ymeU2e76paImgUBDFvBvhby9vLqV3V/FZCd2oqhcb0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=KH+8KyJta4zdeAMZ+3bkFwl34A/7WAPDbP5RZq+lbzPwbocOaRG/iOJ5wsL7jmuG5 +ubLGIB5LJ3516YLj2z7OYqgTerUamnz1IPFYs4Yz5yotNSmbavAOKTENK/qUsZEiC TOpOhURH5o0BX3rSOh7LukhZAZy0IBuD00vfEvws= 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 5.15 519/843] netfilter: xt_u32: reject invalid shift counts Date: Tue, 21 Jul 2026 17:22:34 +0200 Message-ID: <20260721152417.704625677@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152405.946368001@linuxfoundation.org> References: <20260721152405.946368001@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 5.15-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