From: Maurizio Lombardi <mlombard@redhat.com>
Date: Fri, 5 Jan 2024 09:14:44 +0100
Subject: nvmet-tcp: Fix the H2C expected PDU len calculation
Patch-mainline: v6.8-rc1
Git-commit: 9a1abc24850eb759e36a2f8869161c3b7254c904
References: bsc#1217987 bsc#1217988 bsc#1217989 CVE-2023-6535 CVE-2023-6536 CVE-2023-6356

The nvmet_tcp_handle_h2c_data_pdu() function should take into
consideration the possibility that the header digest and/or the data
digests are enabled when calculating the expected PDU length, before
comparing it to the value stored in cmd->pdu_len.

Fixes: efa56305908b ("nvmet-tcp: Fix a kernel panic when host sends an invalid H2C PDU length")
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Acked-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/nvme/target/tcp.c |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -829,7 +829,7 @@ static int nvmet_tcp_handle_h2c_data_pdu
 {
 	struct nvme_tcp_data_pdu *data = &queue->pdu.data;
 	struct nvmet_tcp_cmd *cmd;
-	unsigned int plen;
+	unsigned int exp_data_len;
 
 	cmd = &queue->cmds[data->ttag];
 
@@ -840,9 +840,13 @@ static int nvmet_tcp_handle_h2c_data_pdu
 		goto err_proto;
 	}
 
-	plen = le32_to_cpu(data->hdr.plen);
+	exp_data_len = le32_to_cpu(data->hdr.plen) -
+			nvmet_tcp_hdgst_len(queue) -
+			nvmet_tcp_ddgst_len(queue) -
+			sizeof(*data);
+
 	cmd->pdu_len = le32_to_cpu(data->data_length);
-	if (unlikely(cmd->pdu_len != (plen - sizeof(*data)) ||
+	if (unlikely(cmd->pdu_len != exp_data_len ||
 		     cmd->pdu_len == 0 ||
 		     cmd->pdu_len > NVMET_TCP_MAXH2CDATA)) {
 		pr_err("H2CData PDU len %u is invalid\n", cmd->pdu_len);