[PATCH] usb: xhci: Add error handling in xhci_map_urb_for_dma

[Prashanth K]

Currently xhci_map_urb_for_dma() creates a temporary buffer
and copies the SG list to the new linear buffer. But if the
kzalloc_node() fails, then the following sg_pcopy_to_buffer()
can lead to crash since it tries to memcpy to NULL pointer.
So return -EAGAIN if kzalloc returns null pointer.

Cc: <stable@xxxxxxxxxxxxxxx> # 5.11
Fixes: 2017a1e58472 ("usb: xhci: Use temporary buffer to consolidate SG")
Signed-off-by: Prashanth K <quic_prashk@xxxxxxxxxxx>
---
 drivers/usb/host/xhci.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index c057c42c36f4..0597a60bec34 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1218,6 +1218,9 @@ static int xhci_map_temp_buffer(struct usb_hcd *hcd, struct urb *urb)
 	temp = kzalloc_node(buf_len, GFP_ATOMIC,
 			    dev_to_node(hcd->self.sysdev));
 
+	if (!temp)
+		return -EAGAIN;
+
 	if (usb_urb_dir_out(urb))
 		sg_pcopy_to_buffer(urb->sg, urb->num_sgs,
 				   temp, buf_len, 0);
-- 
2.25.1