This is a note to let you know that I've just added the patch titled

NFC: pn533: don't send USB data off of the stack

to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-testing branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will be merged to the usb-next branch sometime soon, after it passes testing, and the merge window is open.

If you have any questions about this process, please let me know.

From dbafc28955fa6779dc23d1607a0fee5e509a278b Mon Sep 17 00:00:00 2001

From: Greg Kroah-Hartman gregkh@linuxfoundation.org Date: Sun, 20 May 2018 15:19:46 +0200 Subject: NFC: pn533: don't send USB data off of the stack

It's amazing that this driver ever worked, but now that x86 doesn't allow USB data to be sent off of the stack, it really does not work at all. Fix this up by properly allocating the data for the small "commands" that get sent to the device off of the stack.

We do this for one command by having a whole urb just for ack messages, as they can be submitted in interrupt context, so we can not use usb_bulk_msg(). But the poweron command can sleep (and does), so use usb_bulk_msg() for that transfer.

Reported-by: Carlos Manuel Santos cmmpsantos@gmail.com Cc: Samuel Ortiz sameo@linux.intel.com Cc: Stephen Hemminger stephen@networkplumber.org Cc: stable stable@vger.kernel.org Reviewed-by: Johan Hovold johan@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/nfc/pn533/usb.c | 42 +++++++++++++++++++++++++++++------------ 1 file changed, 30 insertions(+), 12 deletions(-)

diff --git a/drivers/nfc/pn533/usb.c b/drivers/nfc/pn533/usb.c index e153e8b64bb8..d5553c47014f 100644 --- a/drivers/nfc/pn533/usb.c +++ b/drivers/nfc/pn533/usb.c @@ -62,6 +62,9 @@ struct pn533_usb_phy { struct urb *out_urb; struct urb *in_urb;

+ struct urb *ack_urb; + u8 *ack_buffer; + struct pn533 *priv; };

@@ -150,13 +153,16 @@ static int pn533_usb_send_ack(struct pn533 *dev, gfp_t flags) struct pn533_usb_phy *phy = dev->phy; static const u8 ack[6] = {0x00, 0x00, 0xff, 0x00, 0xff, 0x00}; /* spec 7.1.1.3: Preamble, SoPC (2), ACK Code (2), Postamble */ - int rc;

- phy->out_urb->transfer_buffer = (u8 *)ack; - phy->out_urb->transfer_buffer_length = sizeof(ack); - rc = usb_submit_urb(phy->out_urb, flags); + if (!phy->ack_buffer) { + phy->ack_buffer = kmemdup(ack, sizeof(ack), flags); + if (!phy->ack_buffer) + return -ENOMEM; + }

- return rc; + phy->ack_urb->transfer_buffer = phy->ack_buffer; + phy->ack_urb->transfer_buffer_length = sizeof(ack); + return usb_submit_urb(phy->ack_urb, flags); }

static int pn533_usb_send_frame(struct pn533 *dev, @@ -375,26 +381,31 @@ static int pn533_acr122_poweron_rdr(struct pn533_usb_phy *phy) /* Power on th reader (CCID cmd) */ u8 cmd[10] = {PN533_ACR122_PC_TO_RDR_ICCPOWERON, 0, 0, 0, 0, 0, 0, 3, 0, 0}; + char *buffer; + int transferred; int rc; void *cntx; struct pn533_acr122_poweron_rdr_arg arg;

dev_dbg(&phy->udev->dev, "%s\n", __func__);

+ buffer = kmemdup(cmd, sizeof(cmd), GFP_KERNEL); + if (!buffer) + return -ENOMEM; + init_completion(&arg.done); cntx = phy->in_urb->context; /* backup context */

phy->in_urb->complete = pn533_acr122_poweron_rdr_resp; phy->in_urb->context = &arg;

- phy->out_urb->transfer_buffer = cmd; - phy->out_urb->transfer_buffer_length = sizeof(cmd); - print_hex_dump_debug("ACR122 TX: ", DUMP_PREFIX_NONE, 16, 1, cmd, sizeof(cmd), false);

- rc = usb_submit_urb(phy->out_urb, GFP_KERNEL); - if (rc) { + rc = usb_bulk_msg(phy->udev, phy->out_urb->pipe, buffer, sizeof(cmd), + &transferred, 0); + kfree(buffer); + if (rc || (transferred != sizeof(cmd))) { nfc_err(&phy->udev->dev, "Reader power on cmd error %d\n", rc); return rc; @@ -490,8 +501,9 @@ static int pn533_usb_probe(struct usb_interface *interface,

phy->in_urb = usb_alloc_urb(0, GFP_KERNEL); phy->out_urb = usb_alloc_urb(0, GFP_KERNEL); + phy->ack_urb = usb_alloc_urb(0, GFP_KERNEL);

- if (!phy->in_urb || !phy->out_urb) + if (!phy->in_urb || !phy->out_urb || !phy->ack_urb) goto error;

usb_fill_bulk_urb(phy->in_urb, phy->udev, @@ -501,7 +513,9 @@ 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); - + usb_fill_bulk_urb(phy->ack_urb, phy->udev, + usb_sndbulkpipe(phy->udev, out_endpoint), + NULL, 0, pn533_send_complete, phy);

switch (id->driver_info) { case PN533_DEVICE_STD: @@ -554,6 +568,7 @@ static int pn533_usb_probe(struct usb_interface *interface, error: usb_free_urb(phy->in_urb); usb_free_urb(phy->out_urb); + usb_free_urb(phy->ack_urb); usb_put_dev(phy->udev); kfree(in_buf);

@@ -573,10 +588,13 @@ static void pn533_usb_disconnect(struct usb_interface *interface)

usb_kill_urb(phy->in_urb); usb_kill_urb(phy->out_urb); + usb_kill_urb(phy->ack_urb);

kfree(phy->in_urb->transfer_buffer); usb_free_urb(phy->in_urb); usb_free_urb(phy->out_urb); + usb_free_urb(phy->ack_urb); + kfree(phy->ack_buffer);

nfc_info(&interface->dev, "NXP PN533 NFC device disconnected\n"); }