| Message ID | 20230306214838.237801-1-pchelkin@ispras.ru (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | nfc: pn533: initialize struct pn533_out_arg properly | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Guessed tree name to be net-next |
| netdev/apply | success | Patch already applied to net-next |
On Tue, Mar 07, 2023 at 12:48:38AM +0300, Fedor Pchelkin wrote: > struct pn533_out_arg used as a temporary context for out_urb is not > initialized properly. Its uninitialized 'phy' field can be dereferenced in > error cases inside pn533_out_complete() callback function. It causes the > following failure: > > general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN > KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] > CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.2.0-rc3-next-20230110-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 > RIP: 0010:pn533_out_complete.cold+0x15/0x44 drivers/nfc/pn533/usb.c:441 > Call Trace: > <IRQ> > __usb_hcd_giveback_urb+0x2b6/0x5c0 drivers/usb/core/hcd.c:1671 > usb_hcd_giveback_urb+0x384/0x430 drivers/usb/core/hcd.c:1754 > dummy_timer+0x1203/0x32d0 drivers/usb/gadget/udc/dummy_hcd.c:1988 > call_timer_fn+0x1da/0x800 kernel/time/timer.c:1700 > expire_timers+0x234/0x330 kernel/time/timer.c:1751 > __run_timers kernel/time/timer.c:2022 [inline] > __run_timers kernel/time/timer.c:1995 [inline] > run_timer_softirq+0x326/0x910 kernel/time/timer.c:2035 > __do_softirq+0x1fb/0xaf6 kernel/softirq.c:571 > invoke_softirq kernel/softirq.c:445 [inline] > __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 > irq_exit_rcu+0x9/0x20 kernel/softirq.c:662 > sysvec_apic_timer_interrupt+0x97/0xc0 arch/x86/kernel/apic/apic.c:1107 > > Initialize the field with the pn533_usb_phy currently used. > > Fixes: 9dab880d675b ("nfc: pn533: Wait for out_urb's completion in pn533_usb_send_frame()") > Reported-by: syzbot+1e608ba4217c96d1952f@syzkaller.appspotmail.com > Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> > --- > drivers/nfc/pn533/usb.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/nfc/pn533/usb.c b/drivers/nfc/pn533/usb.c > index ed9c5e2cf3ad..159b331b3bf6 100644 > --- a/drivers/nfc/pn533/usb.c > +++ b/drivers/nfc/pn533/usb.c > @@ -162,7 +162,7 @@ static int pn533_usb_send_frame(struct pn533 *dev, > struct sk_buff *out) > { > struct pn533_usb_phy *phy = dev->phy; > - struct pn533_out_arg arg; > + struct pn533_out_arg arg = {.phy = phy}; nit: This doesn't follow reverse xmas tree ordering - longest to shortest line. It's probably not worth respinning, but I expect the preferred approach is (*completely untested!*) ... struct pn533_out_arg arg; ... arg.phy = phy; > void *cntx; > int rc; > > -- > 2.34.1 >
On 06/03/2023 22:48, Fedor Pchelkin wrote: > struct pn533_out_arg used as a temporary context for out_urb is not > initialized properly. Its uninitialized 'phy' field can be dereferenced in > error cases inside pn533_out_complete() callback function. It causes the > following failure: > Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Best regards, Krzysztof
On Tue, 7 Mar 2023 16:45:30 +0100 Simon Horman wrote: > nit: This doesn't follow reverse xmas tree ordering - longest to shortest line. > It's probably not worth respinning, but I expect the preferred > approach is (*completely untested!*) > > ... > struct pn533_out_arg arg; > ... > > arg.phy = phy; Let's do it this way. And please make sure that the patch is based on top of the netdev/net tree from git.kernel.org, looks like this version doesn't apply cleanly.
On Tue, Mar 07, 2023 at 04:45:30PM +0100, Simon Horman wrote: > > nit: This doesn't follow reverse xmas tree ordering - longest to shortest line. > It's probably not worth respinning, but I expect the preferred > approach is (*completely untested!*) > > ... > struct pn533_out_arg arg; > ... > > arg.phy = phy; > That is much prettier, thanks for advice! BTW, is reverse xmas tree ordering considered to be a general recommendation for all new kernel patches?
On Thu, Mar 09, 2023 at 07:10:25PM +0300, Fedor Pchelkin wrote: > On Tue, Mar 07, 2023 at 04:45:30PM +0100, Simon Horman wrote: > > > > nit: This doesn't follow reverse xmas tree ordering - longest to shortest line. > > It's probably not worth respinning, but I expect the preferred > > approach is (*completely untested!*) > > > > ... > > struct pn533_out_arg arg; > > ... > > > > arg.phy = phy; > > > > That is much prettier, thanks for advice! > > BTW, is reverse xmas tree ordering considered to be a general > recommendation for all new kernel patches? I think that the situation is that some subsystem maintainers require it, while other's do not. So no.
diff --git a/drivers/nfc/pn533/usb.c b/drivers/nfc/pn533/usb.c index ed9c5e2cf3ad..159b331b3bf6 100644 --- a/drivers/nfc/pn533/usb.c +++ b/drivers/nfc/pn533/usb.c @@ -162,7 +162,7 @@ static int pn533_usb_send_frame(struct pn533 *dev, struct sk_buff *out) { struct pn533_usb_phy *phy = dev->phy; - struct pn533_out_arg arg; + struct pn533_out_arg arg = {.phy = phy}; void *cntx; int rc;
struct pn533_out_arg used as a temporary context for out_urb is not initialized properly. Its uninitialized 'phy' field can be dereferenced in error cases inside pn533_out_complete() callback function. It causes the following failure: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.2.0-rc3-next-20230110-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:pn533_out_complete.cold+0x15/0x44 drivers/nfc/pn533/usb.c:441 Call Trace: <IRQ> __usb_hcd_giveback_urb+0x2b6/0x5c0 drivers/usb/core/hcd.c:1671 usb_hcd_giveback_urb+0x384/0x430 drivers/usb/core/hcd.c:1754 dummy_timer+0x1203/0x32d0 drivers/usb/gadget/udc/dummy_hcd.c:1988 call_timer_fn+0x1da/0x800 kernel/time/timer.c:1700 expire_timers+0x234/0x330 kernel/time/timer.c:1751 __run_timers kernel/time/timer.c:2022 [inline] __run_timers kernel/time/timer.c:1995 [inline] run_timer_softirq+0x326/0x910 kernel/time/timer.c:2035 __do_softirq+0x1fb/0xaf6 kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 irq_exit_rcu+0x9/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x97/0xc0 arch/x86/kernel/apic/apic.c:1107 Initialize the field with the pn533_usb_phy currently used. Fixes: 9dab880d675b ("nfc: pn533: Wait for out_urb's completion in pn533_usb_send_frame()") Reported-by: syzbot+1e608ba4217c96d1952f@syzkaller.appspotmail.com Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> --- drivers/nfc/pn533/usb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)