From: Jia-Ju Bai baijiaju1990@gmail.com
[ Upstream commit a0d57a552b836206ad7705a1060e6e1ce5a38203 ]
In start_isoc_chain(), usb_alloc_urb() on line 1392 may fail and return NULL. At this time, fifo->iso[i].urb is assigned to NULL.
Then, fifo->iso[i].urb is used at some places, such as: LINE 1405: fill_isoc_urb(fifo->iso[i].urb, ...) urb->number_of_packets = num_packets; urb->transfer_flags = URB_ISO_ASAP; urb->actual_length = 0; urb->interval = interval; LINE 1416: fifo->iso[i].urb->... LINE 1419: fifo->iso[i].urb->...
Thus, possible null-pointer dereferences may occur.
To fix these bugs, "continue" is added to avoid using fifo->iso[i].urb when it is NULL.
These bugs are found by a static analysis tool STCheck written by us.
Signed-off-by: Jia-Ju Bai baijiaju1990@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/isdn/hardware/mISDN/hfcsusb.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/isdn/hardware/mISDN/hfcsusb.c b/drivers/isdn/hardware/mISDN/hfcsusb.c index 0e224232f7464..8fb7c5dea07fc 100644 --- a/drivers/isdn/hardware/mISDN/hfcsusb.c +++ b/drivers/isdn/hardware/mISDN/hfcsusb.c @@ -1394,6 +1394,7 @@ start_isoc_chain(struct usb_fifo *fifo, int num_packets_per_urb, printk(KERN_DEBUG "%s: %s: alloc urb for fifo %i failed", hw->name, __func__, fifo->fifonum); + continue; } fifo->iso[i].owner_fifo = (struct usb_fifo *) fifo; fifo->iso[i].indx = i;