From: Fedor Pchelkin pchelkin@ispras.ru
[ Upstream commit 484b7059796e3bc1cb527caa61dfc60da649b4f6 ]
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.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
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 Reviewed-by: Simon Horman simon.horman@corigine.com Link: https://lore.kernel.org/r/20230309165050.207390-1-pchelkin@ispras.ru Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nfc/pn533/usb.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/nfc/pn533/usb.c b/drivers/nfc/pn533/usb.c index 57b07446bb768..68eb1253f888f 100644 --- a/drivers/nfc/pn533/usb.c +++ b/drivers/nfc/pn533/usb.c @@ -175,6 +175,7 @@ static int pn533_usb_send_frame(struct pn533 *dev, print_hex_dump_debug("PN533 TX: ", DUMP_PREFIX_NONE, 16, 1, out->data, out->len, false);
+ arg.phy = phy; init_completion(&arg.done); cntx = phy->out_urb->context; phy->out_urb->context = &arg;