From 9dab880d675b9d0dd56c6428e4e8352a3339371d Mon Sep 17 00:00:00 2001 From: Minsuk Kang Date: Fri, 6 Jan 2023 17:23:44 +0900 Subject: [PATCH] nfc: pn533: Wait for out_urb's completion in pn533_usb_send_frame() Fix a use-after-free that occurs in hcd when in_urb sent from pn533_usb_send_frame() is completed earlier than out_urb. Its callback frees the skb data in pn533_send_async_complete() that is used as a transfer buffer of out_urb. Wait before sending in_urb until the callback of out_urb is called. To modify the callback of out_urb alone, separate the complete function of out_urb and ack_urb. Found by a modified version of syzkaller. BUG: KASAN: use-after-free in dummy_timer Call Trace: memcpy (mm/kasan/shadow.c:65) dummy_perform_transfer (drivers/usb/gadget/udc/dummy_hcd.c:1352) transfer (drivers/usb/gadget/udc/dummy_hcd.c:1453) dummy_timer (drivers/usb/gadget/udc/dummy_hcd.c:1972) arch_static_branch (arch/x86/include/asm/jump_label.h:27) static_key_false (include/linux/jump_label.h:207) timer_expire_exit (include/trace/events/timer.h:127) call_timer_fn (kernel/time/timer.c:1475) expire_timers (kernel/time/timer.c:1519) __run_timers (kernel/time/timer.c:1790) run_timer_softirq (kernel/time/timer.c:1803) Fixes: c46ee38620a2 ("NFC: pn533: add NXP pn533 nfc device driver") Signed-off-by: Minsuk Kang Signed-off-by: David S. Miller --- drivers/nfc/pn533/usb.c | 44 ++++++++++++++++++++++++++++++++++++++--- 1 file changed, 41 insertions(+), 3 deletions(-) diff --git a/drivers/nfc/pn533/usb.c b/drivers/nfc/pn533/usb.c index 6f71ac72012e..ed9c5e2cf3ad 100644 --- a/drivers/nfc/pn533/usb.c +++ b/drivers/nfc/pn533/usb.c @@ -153,10 +153,17 @@ static int pn533_usb_send_ack(struct pn533 *dev, gfp_t flags) return usb_submit_urb(phy->ack_urb, flags); } +struct pn533_out_arg { + struct pn533_usb_phy *phy; + struct completion done; +}; + 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; + void *cntx; int rc; if (phy->priv == NULL) @@ -168,10 +175,17 @@ 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); + init_completion(&arg.done); + cntx = phy->out_urb->context; + phy->out_urb->context = &arg; + rc = usb_submit_urb(phy->out_urb, GFP_KERNEL); if (rc) return rc; + wait_for_completion(&arg.done); + phy->out_urb->context = cntx; + if (dev->protocol_type == PN533_PROTO_REQ_RESP) { /* request for response for sent packet directly */ rc = pn533_submit_urb_for_response(phy, GFP_KERNEL); @@ -408,7 +422,31 @@ static int pn533_acr122_poweron_rdr(struct pn533_usb_phy *phy) return arg.rc; } -static void pn533_send_complete(struct urb *urb) +static void pn533_out_complete(struct urb *urb) +{ + struct pn533_out_arg *arg = urb->context; + struct pn533_usb_phy *phy = arg->phy; + + switch (urb->status) { + case 0: + break; /* success */ + case -ECONNRESET: + case -ENOENT: + dev_dbg(&phy->udev->dev, + "The urb has been stopped (status %d)\n", + urb->status); + break; + case -ESHUTDOWN: + default: + nfc_err(&phy->udev->dev, + "Urb failure (status %d)\n", + urb->status); + } + + complete(&arg->done); +} + +static void pn533_ack_complete(struct urb *urb) { struct pn533_usb_phy *phy = urb->context; @@ -496,10 +534,10 @@ static int pn533_usb_probe(struct usb_interface *interface, usb_fill_bulk_urb(phy->out_urb, phy->udev, usb_sndbulkpipe(phy->udev, out_endpoint), - NULL, 0, pn533_send_complete, phy); + NULL, 0, pn533_out_complete, phy); usb_fill_bulk_urb(phy->ack_urb, phy->udev, usb_sndbulkpipe(phy->udev, out_endpoint), - NULL, 0, pn533_send_complete, phy); + NULL, 0, pn533_ack_complete, phy); switch (id->driver_info) { case PN533_DEVICE_STD: