Commit 8b55d7581fc5 ("NFC: pn533: use constant off-stack buffer for sending
acks"), fixed the ack case of using on stack mem for the transfer_buffer,
by making the ack buffer "static const", which is an unusual solution for
this and I wonder if this is not a problem wrt buffer alignment. It also
misses fixing the same problem for the cmd buffer in the
pn533_acr122_poweron_rdr() function.
This commit introduces an out_buf which gets kmalloc-ed on probe and
then memcpy-s the ack / cmd buffer into that buffer before submitting
the out urb. Fixing the use of on stack memory for the cmd buffer and
moving the ack code-path over to more conventional ways.
While at it this commit also changes the kmalloc of the in_buf to
devm_kmalloc, to avoid the need to introduce a new goto in the error-
handling of the kmalloc of the introduced out_buf.
BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1514134
Fixes: 8b55d7581fc5 ("NFC: pn533: use constant off-stack buffer ...")
Cc: Michał Mirosław <mirq-linux@xxxxxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
drivers/nfc/pn533/usb.c | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/drivers/nfc/pn533/usb.c b/drivers/nfc/pn533/usb.c
index e153e8b64bb8..c9398712ba31 100644
--- a/drivers/nfc/pn533/usb.c
+++ b/drivers/nfc/pn533/usb.c
@@ -42,6 +42,9 @@
#define ACS_VENDOR_ID 0x072f
#define ACR122U_PRODUCT_ID 0x2200
+/* Large enough to hold an ack or the power-on CCID command */
+#define OUT_BUF_LEN 16
+
static const struct usb_device_id pn533_usb_table[] = {
{ USB_DEVICE(PN533_VENDOR_ID, PN533_PRODUCT_ID),
.driver_info = PN533_DEVICE_STD },
@@ -61,6 +64,7 @@ struct pn533_usb_phy {
struct urb *out_urb;
struct urb *in_urb;
+ u8 *out_buf;
struct pn533 *priv;
};
@@ -152,7 +156,8 @@ static int pn533_usb_send_ack(struct pn533 *dev, gfp_t flags)
/* spec 7.1.1.3: Preamble, SoPC (2), ACK Code (2), Postamble */
int rc;
- phy->out_urb->transfer_buffer = (u8 *)ack;
+ memcpy(phy->out_buf, ack, sizeof(ack));
+ phy->out_urb->transfer_buffer = phy->out_buf;
phy->out_urb->transfer_buffer_length = sizeof(ack);
rc = usb_submit_urb(phy->out_urb, flags);
@@ -373,8 +378,8 @@ static void pn533_acr122_poweron_rdr_resp(struct urb *urb)
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};
+ static const u8 cmd[10] = { PN533_ACR122_PC_TO_RDR_ICCPOWERON,
+ 0, 0, 0, 0, 0, 0, 3, 0, 0 };
int rc;
void *cntx;
struct pn533_acr122_poweron_rdr_arg arg;
@@ -387,7 +392,8 @@ static int pn533_acr122_poweron_rdr(struct pn533_usb_phy *phy)
phy->in_urb->complete = pn533_acr122_poweron_rdr_resp;
phy->in_urb->context = &arg;
- phy->out_urb->transfer_buffer = cmd;
+ memcpy(phy->out_buf, cmd, sizeof(cmd));
+ phy->out_urb->transfer_buffer = phy->out_buf;
phy->out_urb->transfer_buffer_length = sizeof(cmd);
print_hex_dump_debug("ACR122 TX: ", DUMP_PREFIX_NONE, 16, 1,
@@ -463,10 +469,14 @@ static int pn533_usb_probe(struct usb_interface *interface,
if (!phy)
return -ENOMEM;
- in_buf = kzalloc(in_buf_len, GFP_KERNEL);
+ in_buf = devm_kzalloc(&interface->dev, in_buf_len, GFP_KERNEL);
if (!in_buf)
return -ENOMEM;
+ phy->out_buf = devm_kzalloc(&interface->dev, OUT_BUF_LEN, GFP_KERNEL);
+ if (!phy->out_buf)
+ return -ENOMEM;
+
phy->udev = usb_get_dev(interface_to_usbdev(interface));
phy->interface = interface;
@@ -555,7 +565,6 @@ static int pn533_usb_probe(struct usb_interface *interface,
usb_free_urb(phy->in_urb);
usb_free_urb(phy->out_urb);
usb_put_dev(phy->udev);
- kfree(in_buf);
return rc;
}
@@ -574,7 +583,6 @@ static void pn533_usb_disconnect(struct usb_interface *interface)
usb_kill_urb(phy->in_urb);
usb_kill_urb(phy->out_urb);
- kfree(phy->in_urb->transfer_buffer);
usb_free_urb(phy->in_urb);
usb_free_urb(phy->out_urb);
