From 1dd5b819f7e406dc15bbc7670596ff25261aaa2a Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Wed, 24 Nov 2021 17:50:41 +0300 Subject: [PATCH] can: sja1000: fix use after free in ems_pcmcia_add_card() commit 3ec6ca6b1a8e64389f0212b5a1b0f6fed1909e45 upstream. If the last channel is not available then "dev" is freed. Fortunately, we can just use "pdev->irq" instead. Also we should check if at least one channel was set up. Fixes: fd734c6f25ae ("can/sja1000: add driver for EMS PCMCIA card") Link: https://lore.kernel.org/all/20211124145041.GB13656@kili Cc: stable@vger.kernel.org Signed-off-by: Dan Carpenter Acked-by: Oliver Hartkopp Tested-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/sja1000/ems_pcmcia.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/sja1000/ems_pcmcia.c b/drivers/net/can/sja1000/ems_pcmcia.c index 381de998d2f1..fef5c59c0f4c 100644 --- a/drivers/net/can/sja1000/ems_pcmcia.c +++ b/drivers/net/can/sja1000/ems_pcmcia.c @@ -243,7 +243,12 @@ static int ems_pcmcia_add_card(struct pcmcia_device *pdev, unsigned long base) free_sja1000dev(dev); } - err = request_irq(dev->irq, &ems_pcmcia_interrupt, IRQF_SHARED, + if (!card->channels) { + err = -ENODEV; + goto failure_cleanup; + } + + err = request_irq(pdev->irq, &ems_pcmcia_interrupt, IRQF_SHARED, DRV_NAME, card); if (!err) return 0; -- 2.20.1