The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From dda32c00c9a0fa103b5d54ef72c477b7aa993679 Mon Sep 17 00:00:00 2001
From: Christophe JAILLET christophe.jaillet@wanadoo.fr Date: Wed, 12 May 2021 11:08:14 +0300 Subject: [PATCH] xhci: Do not use GFP_KERNEL in (potentially) atomic context
'xhci_urb_enqueue()' is passed a 'mem_flags' argument, because "URBs may be submitted in interrupt context" (see comment related to 'usb_submit_urb()' in 'drivers/usb/core/urb.c')
So this flag should be used in all the calling chain. Up to now, 'xhci_check_maxpacket()' which is only called from 'xhci_urb_enqueue()', uses GFP_KERNEL.
Be safe and pass the mem_flags to this function as well.
Fixes: ddba5cd0aeff ("xhci: Use command structures when queuing commands on the command ring") Cc: stable@vger.kernel.org Signed-off-by: Christophe JAILLET christophe.jaillet@wanadoo.fr Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com Link: https://lore.kernel.org/r/20210512080816.866037-4-mathias.nyman@linux.intel.... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index ca9385d22f68..27283654ca08 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -1514,7 +1514,7 @@ static int xhci_configure_endpoint(struct xhci_hcd *xhci, * we need to issue an evaluate context command and wait on it. */ static int xhci_check_maxpacket(struct xhci_hcd *xhci, unsigned int slot_id, - unsigned int ep_index, struct urb *urb) + unsigned int ep_index, struct urb *urb, gfp_t mem_flags) { struct xhci_container_ctx *out_ctx; struct xhci_input_control_ctx *ctrl_ctx; @@ -1545,7 +1545,7 @@ static int xhci_check_maxpacket(struct xhci_hcd *xhci, unsigned int slot_id, * changes max packet sizes. */
- command = xhci_alloc_command(xhci, true, GFP_KERNEL); + command = xhci_alloc_command(xhci, true, mem_flags); if (!command) return -ENOMEM;
@@ -1639,7 +1639,7 @@ static int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag */ if (urb->dev->speed == USB_SPEED_FULL) { ret = xhci_check_maxpacket(xhci, slot_id, - ep_index, urb); + ep_index, urb, mem_flags); if (ret < 0) { xhci_urb_free_priv(urb_priv); urb->hcpriv = NULL;