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 916893EBF24; Mon, 20 Apr 2026 13:25:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776691508; cv=none; b=kpYlHzh7sESowi/BPjXSuwF+Y4cpTZO2Sk8t/RXrCWMG69ZFdTbLwRqWojqAYdK/ZnfDeYEJrf1+btrOF8mwDkma2I94pRfKM7vTMkLSG12Qa5HaNGHK0MlYKg12IPdwskk9xLkUH/WytvzfJOa2LnbJeTnEVt9qSQij91jyER4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776691508; c=relaxed/simple; bh=Tm2TK+2FNVWxTTlWKNIQ+aQP0xbWrywECEF+yY3Ixt4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Aiiofg/iqybEmkFTwFArRsL95L8y0QvqEVK7NFE8T0hFHtMb703AxHynLG4zeakSDpaF9k/ZiLCc4uE9yHcD8safDaOfdm9Y5oY85LRs7aslhHhQITCChliSqEfCSEuc5MeVeiCHlaeEXtfhzsBY1XngtwuuVd8uvcM5FUFKBeI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DCE1YcQW; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DCE1YcQW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9FCBDC2BCB4; Mon, 20 Apr 2026 13:25:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776691508; bh=Tm2TK+2FNVWxTTlWKNIQ+aQP0xbWrywECEF+yY3Ixt4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DCE1YcQWOQ0+XgQKAf/KtQTijLPwf4g++MahK6HCi1mM/vM3+4yjuP/DGJujMKr0F IHAxNfsoyDU/Za6F1E2vVVSWLdONlz3kTAbgESbUF3w74xn+jSsEudrf+DwPWk82Cd FemvZFCXcdzXz2FXzm2YDPnKWl1w1szUsUPJ6NdPejZeZQgAkeizbR33F3MNt5u+KO O+VsUmzMNyLI7eCG7cS//wwDZHtIBjeXiuOovMYCi3otKaeNyTSABRhSVvSseMVHJf EdMHP05rNty1Srzbl4Qhk57whTtlvz5EeZ2a8N8nUXbnq7L/xsCG1aZzC89I1pE2N5 eZ4dZ9I9Q6TUA== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: Xiang Mei , Weiming Shi , Florian Westphal , Sasha Levin , pablo@netfilter.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, kaber@trash.net, eric@inl.fr, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH AUTOSEL 6.18] netfilter: nfnetlink_log: initialize nfgenmsg in NLMSG_DONE terminator Date: Mon, 20 Apr 2026 09:17:45 -0400 Message-ID: <20260420132314.1023554-71-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260420132314.1023554-1-sashal@kernel.org> References: <20260420132314.1023554-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.18.23 Content-Transfer-Encoding: 8bit From: Xiang Mei [ Upstream commit 1f3083aec8836213da441270cdb1ab612dd82cf4 ] When batching multiple NFLOG messages (inst->qlen > 1), __nfulnl_send() appends an NLMSG_DONE terminator with sizeof(struct nfgenmsg) payload via nlmsg_put(), but never initializes the nfgenmsg bytes. The nlmsg_put() helper only zeroes alignment padding after the payload, not the payload itself, so four bytes of stale kernel heap data are leaked to userspace in the NLMSG_DONE message body. Use nfnl_msg_put() to build the NLMSG_DONE terminator, which initializes the nfgenmsg payload via nfnl_fill_hdr(), consistent with how __build_packet_message() already constructs NFULNL_MSG_PACKET headers. Fixes: 29c5d4afba51 ("[NETFILTER]: nfnetlink_log: fix sending of multipart messages") Reported-by: Weiming Shi Signed-off-by: Xiang Mei Signed-off-by: Florian Westphal Signed-off-by: Sasha Levin --- LLM Generated explanations, may be completely bogus: Error: Failed to generate final synthesis net/netfilter/nfnetlink_log.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c index dcd2493a9a404..b1f3eda85989c 100644 --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -361,10 +361,10 @@ static void __nfulnl_send(struct nfulnl_instance *inst) { if (inst->qlen > 1) { - struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0, - NLMSG_DONE, - sizeof(struct nfgenmsg), - 0); + struct nlmsghdr *nlh = nfnl_msg_put(inst->skb, 0, 0, + NLMSG_DONE, 0, + AF_UNSPEC, NFNETLINK_V0, + htons(inst->group_num)); if (WARN_ONCE(!nlh, "bad nlskb size: %u, tailroom %d\n", inst->skb->len, skb_tailroom(inst->skb))) { kfree_skb(inst->skb); -- 2.53.0