[PATCH] nvmet-tcp: add bound check on Transfer Tag

[Varun Prakash]

ttag is used as an index to get cmd in nvmet_tcp_handle_h2c_data_pdu(),
add a bound check to avoid out-of-bounds access.

Signed-off-by: Varun Prakash <varun at chelsio.com>
---
 drivers/nvme/target/tcp.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index 02df2fc7dfe7..6729c384f2bb 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -935,10 +935,17 @@ static int nvmet_tcp_handle_h2c_data_pdu(struct nvmet_tcp_queue *queue)
 	struct nvme_tcp_data_pdu *data = &queue->pdu.data;
 	struct nvmet_tcp_cmd *cmd;
 
-	if (likely(queue->nr_cmds))
+	if (likely(queue->nr_cmds)) {
+		if (unlikely(data->ttag >= queue->nr_cmds)) {
+			pr_err("queue %d: received out of bound ttag %u, nr_cmds %u\n",
+				queue->idx, data->ttag, queue->nr_cmds);
+			nvmet_tcp_fatal_error(queue);
+			return -EPROTO;
+		}
 		cmd = &queue->cmds[data->ttag];
-	else
+	} else {
 		cmd = &queue->connect;
+	}
 
 	if (le32_to_cpu(data->data_offset) != cmd->rbytes_done) {
 		pr_err("ttag %u unexpected data offset %u (expected %u)\n",
-- 
2.31.1