tree 26dae4806595cc0b4a62e930a2352cad5cce812a
parent c4e94174983a86c935be1537a73e496b778b0287
author Clemens Gruber <clemens.gruber@pqgruber.com> 1473096598 +0200
committer Peter Chen <peter.chen@nxp.com> 1473412797 +0800

usb: chipidea: udc: fix NULL ptr dereference in isr_setup_status_phase

Problems with the signal integrity of the high speed USB data lines or
noise on reference ground lines can cause the i.MX6 USB controller to
violate USB specs and exhibit unexpected behavior.

It was observed that USBi_UI interrupts were triggered first and when
isr_setup_status_phase was called, ci->status was NULL, which lead to a
NULL pointer dereference kernel panic.

This patch fixes the kernel panic, emits a warning once and returns
-EPIPE to halt the device and let the host get stalled.
It also adds a comment to point people, who are experiencing this issue,
to their USB hardware design.

Cc: <stable@vger.kernel.org> #4.1+
Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>