2024-02-28 12:58:17

by Prashanth K

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

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: <[email protected]> # 5.11
Fixes: 2017a1e58472 ("usb: xhci: Use temporary buffer to consolidate SG")
Signed-off-by: Prashanth K <[email protected]>
---
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

2024-02-29 21:22:23

by Mathias Nyman

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

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: <[email protected]> # 5.11
> Fixes: 2017a1e58472 ("usb: xhci: Use temporary buffer to consolidate SG")
> Signed-off-by: Prashanth K <[email protected]>
> ---

Thanks.

Added

-Mathias