On Sat, Apr 04, 2020 at 12:18:38PM +0800, Qiujun Huang wrote: > In ath9k_hif_usb_rx_cb interface number is assumed to be 0. > usb_ifnum_to_if(urb->dev, 0) > But it isn't always true. > > The case reported by syzbot: > https://lore.kernel.org/linux-usb/000000000000666c9c05a1c05d12@xxxxxxxxxx > usb 2-1: new high-speed USB device number 2 using dummy_hcd > usb 2-1: config 1 has an invalid interface number: 2 but max is 0 > usb 2-1: config 1 has no interface number 0 > usb 2-1: New USB device found, idVendor=0cf3, idProduct=9271, bcdDevice= > 1.08 > usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 > general protection fault, probably for non-canonical address > 0xdffffc0000000015: 0000 [#1] SMP KASAN > KASAN: null-ptr-deref in range [0x00000000000000a8-0x00000000000000af] > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc5-syzkaller #0 > > Call Trace > __usb_hcd_giveback_urb+0x29a/0x550 drivers/usb/core/hcd.c:1650 > usb_hcd_giveback_urb+0x368/0x420 drivers/usb/core/hcd.c:1716 > dummy_timer+0x1258/0x32ae drivers/usb/gadget/udc/dummy_hcd.c:1966 > call_timer_fn+0x195/0x6f0 kernel/time/timer.c:1404 > expire_timers kernel/time/timer.c:1449 [inline] > __run_timers kernel/time/timer.c:1773 [inline] > __run_timers kernel/time/timer.c:1740 [inline] > run_timer_softirq+0x5f9/0x1500 kernel/time/timer.c:1786 > __do_softirq+0x21e/0x950 kernel/softirq.c:292 > invoke_softirq kernel/softirq.c:373 [inline] > irq_exit+0x178/0x1a0 kernel/softirq.c:413 > exiting_irq arch/x86/include/asm/apic.h:546 [inline] > smp_apic_timer_interrupt+0x141/0x540 arch/x86/kernel/apic/apic.c:1146 > apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 > > Reported-and-tested-by: syzbot+40d5d2e8a4680952f042@xxxxxxxxxxxxxxxxxxxxxxxxx > Signed-off-by: Qiujun Huang <hqjagain@xxxxxxxxx> > --- > drivers/net/wireless/ath/ath9k/hif_usb.c | 48 ++++++++++++++++++------ > drivers/net/wireless/ath/ath9k/hif_usb.h | 5 +++ > 2 files changed, 42 insertions(+), 11 deletions(-) > > diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c > index 6049d3766c64..4ed21dad6a8e 100644 > --- a/drivers/net/wireless/ath/ath9k/hif_usb.c > +++ b/drivers/net/wireless/ath/ath9k/hif_usb.c > @@ -643,9 +643,9 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev, > > static void ath9k_hif_usb_rx_cb(struct urb *urb) > { > - struct sk_buff *skb = (struct sk_buff *) urb->context; > - struct hif_device_usb *hif_dev = > - usb_get_intfdata(usb_ifnum_to_if(urb->dev, 0)); > + struct rx_buf *rx_buf = (struct rx_buf *)urb->context; > + struct hif_device_usb *hif_dev = rx_buf->hif_dev; > + struct sk_buff *skb = rx_buf->skb; > int ret; > > if (!skb) This "if (!skb)" error path returns directly and leaks "rx_buf". Of course, it's an impossible condition. We should just delete the check. > @@ -685,14 +685,15 @@ static void ath9k_hif_usb_rx_cb(struct urb *urb) > return; > free: > kfree_skb(skb); > + kfree(rx_buf); > } > > static void ath9k_hif_usb_reg_in_cb(struct urb *urb) > { > - struct sk_buff *skb = (struct sk_buff *) urb->context; > + struct rx_buf *rx_buf = (struct rx_buf *)urb->context; > + struct hif_device_usb *hif_dev = rx_buf->hif_dev; > + struct sk_buff *skb = rx_buf->skb; > struct sk_buff *nskb; > - struct hif_device_usb *hif_dev = > - usb_get_intfdata(usb_ifnum_to_if(urb->dev, 0)); > int ret; > > if (!skb) Same. > @@ -750,6 +751,7 @@ static void ath9k_hif_usb_reg_in_cb(struct urb *urb) > return; > free: > kfree_skb(skb); > + kfree(rx_buf); > urb->context = NULL; > } > regards, dan carpenter
