[RFT PATCH] xhci: Fix null pointer dereference in resume if xhci has only one roothub
Matthias Kaehlcke
mka at chromium.org
Thu Jun 9 08:41:36 PDT 2022
On Thu, Jun 09, 2022 at 03:03:36PM +0300, Mathias Nyman wrote:
> In the re-init path xhci_resume() passes 'hcd->primary_hcd' to hci_init(),
> however this field isn't initialized by __usb_create_hcd() for a HCD
> without secondary controller.
>
> xhci_resume() is called once per xHC device, not per hcd, so the extra
> checking for primary hcd can be removed.
>
> Fixes: e0fe986972f5 ("usb: host: xhci-plat: prepare operation w/o shared hcd")
> Reported-by: Matthias Kaehlcke <mka at chromium.org>
> Signed-off-by: Mathias Nyman <mathias.nyman at linux.intel.com>
> ---
> drivers/usb/host/xhci.c | 15 +++++----------
> 1 file changed, 5 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index f0ab63138016..9ac56e9ffc64 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -1107,7 +1107,6 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
> {
> u32 command, temp = 0;
> struct usb_hcd *hcd = xhci_to_hcd(xhci);
> - struct usb_hcd *secondary_hcd;
> int retval = 0;
> bool comp_timer_running = false;
> bool pending_portevent = false;
> @@ -1214,23 +1213,19 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
> * first with the primary HCD, and then with the secondary HCD.
> * If we don't do the same, the host will never be started.
> */
> - if (!usb_hcd_is_primary_hcd(hcd))
> - secondary_hcd = hcd;
> - else
> - secondary_hcd = xhci->shared_hcd;
> -
> xhci_dbg(xhci, "Initialize the xhci_hcd\n");
> - retval = xhci_init(hcd->primary_hcd);
> + retval = xhci_init(hcd);
> if (retval)
> return retval;
> comp_timer_running = true;
>
> xhci_dbg(xhci, "Start the primary HCD\n");
Is the log still correct? IIUC this now isn't necessarily the primary HCD.
> - retval = xhci_run(hcd->primary_hcd);
> - if (!retval && secondary_hcd) {
> + retval = xhci_run(hcd);
> + if (!retval && xhci->shared_hcd) {
> xhci_dbg(xhci, "Start the secondary HCD\n");
ditto
> - retval = xhci_run(secondary_hcd);
> + retval = xhci_run(xhci->shared_hcd);
> }
> +
> hcd->state = HC_STATE_SUSPENDED;
> if (xhci->shared_hcd)
> xhci->shared_hcd->state = HC_STATE_SUSPENDED;
Tested-by: Matthias Kaehlcke <mka at chromium.org>
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