From: Zheyu Ma zheyuma97@gmail.com

When remove the module peek_pci, referencing 'chan' again after releasing 'dev' will cause UAF.

Fix this by releasing 'dev' later.

The following log reveals it:

[ 35.961814 ] BUG: KASAN: use-after-free in peak_pci_remove+0x16f/0x270 [peak_pci] [ 35.963414 ] Read of size 8 at addr ffff888136998ee8 by task modprobe/5537 [ 35.965513 ] Call Trace: [ 35.965718 ] dump_stack_lvl+0xa8/0xd1 [ 35.966028 ] print_address_description+0x87/0x3b0 [ 35.966420 ] kasan_report+0x172/0x1c0 [ 35.966725 ] ? peak_pci_remove+0x16f/0x270 [peak_pci] [ 35.967137 ] ? trace_irq_enable_rcuidle+0x10/0x170 [ 35.967529 ] ? peak_pci_remove+0x16f/0x270 [peak_pci] [ 35.967945 ] __asan_report_load8_noabort+0x14/0x20 [ 35.968346 ] peak_pci_remove+0x16f/0x270 [peak_pci] [ 35.968752 ] pci_device_remove+0xa9/0x250

Fixes: e6d9c80b7ca1 ("can: peak_pci: add support of some new PEAK-System PCI cards") Link: https://lore.kernel.org/all/1634192913-15639-1-git-send-email-zheyuma97@gmai... Cc: stable@vger.kernel.org Signed-off-by: Zheyu Ma zheyuma97@gmail.com Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de --- drivers/net/can/sja1000/peak_pci.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/net/can/sja1000/peak_pci.c b/drivers/net/can/sja1000/peak_pci.c index 6db90dc4bc9d..84f34020aafb 100644 --- a/drivers/net/can/sja1000/peak_pci.c +++ b/drivers/net/can/sja1000/peak_pci.c @@ -752,16 +752,15 @@ static void peak_pci_remove(struct pci_dev *pdev) struct net_device *prev_dev = chan->prev_dev;

dev_info(&pdev->dev, "removing device %s\n", dev->name); + /* do that only for first channel */ + if (!prev_dev && chan->pciec_card) + peak_pciec_remove(chan->pciec_card); unregister_sja1000dev(dev); free_sja1000dev(dev); dev = prev_dev;

- if (!dev) { - /* do that only for first channel */ - if (chan->pciec_card) - peak_pciec_remove(chan->pciec_card); + if (!dev) break; - } priv = netdev_priv(dev); chan = priv->priv; }