[PATCH 4.9 074/177] libertas: check return value of alloc_workqueue

From: Greg Kroah-Hartman
Date: Fri Mar 23 2018 - 06:08:12 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Pan Bian <bianpan2016@xxxxxxx>


[ Upstream commit dc3f89c38a8406554ffeffa370aad086a9c5e9de ]

Function alloc_workqueue() will return a NULL pointer if there is no
enough memory, and its return value should be validated before using.
However, in function if_spi_probe(), its return value is not checked.
This may result in a NULL dereference bug. This patch fixes the bug.

Signed-off-by: Pan Bian <bianpan2016@xxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/wireless/marvell/libertas/if_spi.c | 5 +++++
1 file changed, 5 insertions(+)

--- a/drivers/net/wireless/marvell/libertas/if_spi.c
+++ b/drivers/net/wireless/marvell/libertas/if_spi.c
@@ -1181,6 +1181,10 @@ static int if_spi_probe(struct spi_devic

/* Initialize interrupt handling stuff. */
card->workqueue = alloc_workqueue("libertas_spi", WQ_MEM_RECLAIM, 0);
+ if (!card->workqueue) {
+ err = -ENOMEM;
+ goto remove_card;
+ }
INIT_WORK(&card->packet_work, if_spi_host_to_card_worker);
INIT_WORK(&card->resume_work, if_spi_resume_worker);

@@ -1209,6 +1213,7 @@ release_irq:
free_irq(spi->irq, card);
terminate_workqueue:
destroy_workqueue(card->workqueue);
+remove_card:
lbs_remove_card(priv); /* will call free_netdev */
free_card:
free_if_spi_card(card);