xhci: fix possible null pointer dereference at secondary interrupter removal

Don't try to remove a secondary interrupter that is known to be invalid.
Also check if the interrupter is valid inside the spinlock that protects
the array of interrupters.

Found by smatch static checker

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-usb/ffaa0a1b-5984-4a1f-bfd3-9184630a97b9@moroto.mountain/
Fixes: c99b38c412 ("xhci: add support to allocate several interrupters")
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20240125152737.2983959-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mathias Nyman 2024-01-25 17:27:34 +02:00 committed by Greg Kroah-Hartman
parent 9dc292413c
commit a54a594d72

View file

@ -1861,15 +1861,15 @@ void xhci_remove_secondary_interrupter(struct usb_hcd *hcd, struct xhci_interrup
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
unsigned int intr_num;
/* interrupter 0 is primary interrupter, don't touch it */
if (!ir || !ir->intr_num || ir->intr_num >= xhci->max_interrupters)
xhci_dbg(xhci, "Invalid secondary interrupter, can't remove\n");
/* fixme, should we check xhci->interrupter[intr_num] == ir */
/* fixme locking */
spin_lock_irq(&xhci->lock);
/* interrupter 0 is primary interrupter, don't touch it */
if (!ir || !ir->intr_num || ir->intr_num >= xhci->max_interrupters) {
xhci_dbg(xhci, "Invalid secondary interrupter, can't remove\n");
spin_unlock_irq(&xhci->lock);
return;
}
intr_num = ir->intr_num;
xhci_remove_interrupter(xhci, ir);