nvmet-tcp: add bounds check on Transfer Tag

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

Signed-off-by: Varun Prakash <varun@chelsio.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index 1762e2e..98e17ea 100644 (file)
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -920,10 +920,17 @@ 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",