Commit c207979f authored by Arthur Kiyanovski's avatar Arthur Kiyanovski Committed by David S. Miller
Browse files

net: ena: ena-com.c: prevent NULL pointer dereference 



comp_ctx can be NULL in a very rare case when an admin command is executed
during the execution of ena_remove().

The bug scenario is as follows:

* ena_destroy_device() sets the comp_ctx to be NULL
* An admin command is executed before executing unregister_netdev(),
  this can still happen because our device can still receive callbacks
  from the netdev infrastructure such as ethtool commands.
* When attempting to access the comp_ctx, the bug occurs since it's set
  to NULL

Fix:
Added a check that comp_ctx is not NULL

Fixes: 1738cd3e ("net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: default avatarSameeh Jubran <sameehj@amazon.com>
Signed-off-by: default avatarArthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 886d2089

drivers/net/ethernet/amazon/ena/ena_com.c

+5 −0
Original line number Diff line number Diff line
@@ -200,6 +200,11 @@ static void comp_ctxt_release(struct ena_com_admin_queue *queue, 
static struct ena_comp_ctx *get_comp_ctxt(struct ena_com_admin_queue *queue,

					  u16 command_id, bool capture)

{

	if (unlikely(!queue->comp_ctx)) {

		pr_err("Completion context is NULL\n");

		return NULL;

	}



	if (unlikely(command_id >= queue->q_depth)) {

		pr_err("command id is larger than the queue size. cmd_id: %u queue size %d\n",

		       command_id, queue->q_depth);