[v2] usb: xhci: Add error handling in xhci_map_urb_for_dma

[v2] 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 -ENOMEM if kzalloc returns null pointer.

Cc: <stable@vger.kernel.org> # 5.11
Fixes: 2017a1e58472 ("usb: xhci: Use temporary buffer to consolidate SG")
Signed-off-by: Prashanth K <quic_prashk@quicinc.com>
---
v2: Updated -EAGAIN to -ENOMEM

 drivers/usb/host/xhci.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index c057c42c36f4..35e9efdee3b2 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1217,6 +1217,8 @@ 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 -ENOMEM;
 
 	if (usb_urb_dir_out(urb))
 		sg_pcopy_to_buffer(urb->sg, urb->num_sgs,
-- 
2.25.1

Re: [v2] usb: xhci: Add error handling in xhci_map_urb_for_dma

[Mathias Nyman]

On 28.2.2024 14.57, Prashanth K wrote:
> 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 -ENOMEM if kzalloc returns null pointer.
> 
> Cc: <stable@vger.kernel.org> # 5.11
> Fixes: 2017a1e58472 ("usb: xhci: Use temporary buffer to consolidate SG")
> Signed-off-by: Prashanth K <quic_prashk@quicinc.com>
> ---

Thanks.

Added

-Mathias