From: Dan Carpenter dan.carpenter@oracle.com

stable inclusion from stable-v4.19.221 commit ccf070183e4655824936c0f96c4a2bcca93419aa category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9S254 CVE: CVE-2021-47521

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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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 dan.carpenter@oracle.com Acked-by: Oliver Hartkopp socketcan@hartkopp.net Tested-by: Oliver Hartkopp socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Chen Zhongjin chenzhongjin@huawei.com --- 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;