| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 021/126] net: ena: ena-com.c: prevent NULL pointer dereference | Date | Tue, 10 Mar 2020 13:40:42 +0100 |
| |
From: Arthur Kiyanovski <akiyano@amazon.com>
[ Upstream commit c207979f5ae10ed70aff1bb13f39f0736973de99 ]
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: 1738cd3ed342 ("net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)") Signed-off-by: Sameeh Jubran <sameehj@amazon.com> Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/net/ethernet/amazon/ena/ena_com.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/net/ethernet/amazon/ena/ena_com.c b/drivers/net/ethernet/amazon/ena/ena_com.c index 552db5399503f..31e0cf1442012 100644 --- a/drivers/net/ethernet/amazon/ena/ena_com.c +++ b/drivers/net/ethernet/amazon/ena/ena_com.c @@ -199,6 +199,11 @@ static inline 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); -- 2.20.1
|