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 CBD58370AE5; Sat, 12 Sep 2026 13:56:31 +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=1789221392; cv=none; b=bljuWiuB1daPQzMhUsQYJmarAQeTao8YGDQMNqbUeRosVjlteyR4j/O5UCuMQ1KFC/H5kX+6W5e4aoi9brm2vIAiMVWHNlKQenwN1MOsacZRiATlGS1CLu+polMq08NbTVWM3daJ1eMqEOHwxOQD9MiTpYMKl1krpzfRCFc5u6A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789221392; c=relaxed/simple; bh=xqjjJLM8ugQ+cKSpyvRrXgB8PXBkf2Yf2SlTtm+OpmQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TTs5gYMjAiSLLSkv4p+V4gbHYyMmB8BP0ZEqOSGmsVrK7mfPoFg6q8kxoS70lHCkaSWDQyDu9JAINnnjHLuH32g23AFkVgBeQ/jzQRNVYcvmBycDl9792QC6OrhTDjVXy6usB+DnPXs15QHz6y2FLOKvgG4jMkD2WO0uJL1uUwE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LTsl5E3U; 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="LTsl5E3U" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EA70E1F000FF; Sat, 12 Sep 2026 13:56:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789221391; bh=lOVC7ppqnqGksnrvg/y4pcpMo6Dj6QPEY72hD2E4avs=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=LTsl5E3UxyHL+TsiHaai8e52lyDxxORy/BuYNG253lA6pQ7cOLsPHZzq4sSRyZcpH LxC6cpunpZ4cXiW1qpYLpvdv0mY+oPe91sGmpYiol3/tiyNmQe7nObv4gX+m4VtZyJ ctm3RMjoJFXFGrzIRFxFAbEln7Jhxj0fpgV8XHRk= 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 6.6 0373/1424] nvmet-tcp: fix out-of-bounds write when receiving an over-long PDU Date: Sat, 12 Sep 2026 08:46:45 +0200 Message-ID: <20260912065615.646176880@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.279695368@linuxfoundation.org> References: <20260912065607.279695368@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: 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 @@ -1231,6 +1231,8 @@ recv: } queue->left = hdr->hlen - queue->offset + hdgst; + if (queue->left > sizeof(queue->pdu) - queue->offset) + return -EPROTO; goto recv; }