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 7DC1C369224; Sat, 12 Sep 2026 11:41:25 +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=1789213286; cv=none; b=jFBqKPW0jBFJpaWjIfzW+N10qWZu3D9dyQH7FUxoMaTERSo89C/nLqhSeoyxnmeRZE9JOmMsmzoBJPL7CyaxHTbf9gjR1npLlg7+wB6a7UdcgER9St5TQDoP5JnTuvZLDDolH4Bpu+wUkTaSUcSKRH2oSaLIZxtQAK4KmjvPL/s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789213286; c=relaxed/simple; bh=JYMMlpigLhIP6ZgCk183v1GJmTQDvVOK3Zn0B81YYUE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YfWl+HG3MPhOA9S83susclu9zYL47wUIJznevZtehvnGrLyV07JfAyVo3NSdqfjpc0rnKIkW3ydSTQpRoDN1oumD/F3Vx0jHsCY7SW3KeN3F5JNemshjYnlzoOk/wHg8m8wZkZqSoEwuu9ywv6ElxoIypUjR9IEgNsjuLN8WdGI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=O1lYQG7Z; 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="O1lYQG7Z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD8641F000FF; Sat, 12 Sep 2026 11:41:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789213285; bh=HJQMjYiA7xRPar+NNr++loboN87JcjX0ha6tV6sCWfU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=O1lYQG7ZOMCAE1Ns9a4WluqRNd6gS8py+gl0k4OrkWvmbtBBQvRrM9Y0D5gNQVxsb KeLtiXyU9OFzfqEl+2qGWRV54/soUzSoEwMTE7lMfpTW7ARIhpe1TCPf2LaZErRV6c CIDXh+opGVXzcjCO+vyBHcIIxdX12OqNeDq5LuYQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shivam Kumar , Sagi Grimberg , Keith Busch Subject: [PATCH 6.12 0088/1376] nvmet-tcp: fix out-of-bounds write when receiving an over-long PDU Date: Sat, 12 Sep 2026 08:41:54 +0200 Message-ID: <20260912065609.520869631@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.535295758@linuxfoundation.org> References: <20260912065607.535295758@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org 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: Shivam Kumar commit 14cc5a7e77731497d5bea70f3bb05df7eda982e4 upstream. nvmet_tcp_try_recv_pdu() reads a PDU header into the fixed 128-byte queue->pdu union, then computes the remaining payload length as queue->left = hdr->hlen - queue->offset + hdgst; and reads that many more bytes into &queue->pdu + queue->offset, without ever bounding the result against sizeof(queue->pdu). A struct nvme_tcp_icreq_pdu is itself 128 bytes, exactly the size of the union. Once a header digest has been negotiated (hdgst = 4), a second ICReq passes the hlen == nvmet_tcp_pdu_size() check but yields queue->left = 128 - 8 + 4 = 124, so bytes 8..132 are written into the 128-byte buffer -- 4 bytes past its end, over queue->hdr_digest and queue->data_digest. Those bytes are attacker-controlled (an ICReq carries no digest), and the duplicate ICReq is only rejected later, after the overflow. A remote unauthenticated host can thus corrupt kernel memory adjacent to the receive buffer. Reject any PDU whose declared length would read past the end of queue->pdu before the second recv. Fixes: 872d26a391da ("nvmet-tcp: add NVMe over TCP target driver") Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Shivam Kumar Cc: stable@vger.kernel.org Reviewed-by: Sagi Grimberg Signed-off-by: Keith Busch Signed-off-by: Greg Kroah-Hartman --- drivers/nvme/target/tcp.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/nvme/target/tcp.c +++ b/drivers/nvme/target/tcp.c @@ -1301,6 +1301,8 @@ recv: } queue->left = hdr->hlen - queue->offset + hdgst; + if (queue->left > sizeof(queue->pdu) - queue->offset) + return -EPROTO; goto recv; }