Re: [PATCH] usb: xhci: Fix ep0 maxpacket update on enabled slots

[sashiko-bot@kernel.org]

> A slot in Enabled state has uninitialized output contexts;
> it doesn't need and cannot accept Evaluate Context command.
> Attempting the command only results in a (harmless) warning,
> observed when core uses "old scheme" on a full-speed device:
> 
>   WARN: invalid context state for evaluate context command.
> 
> This problem doesn't seem to have existed before ep0 update
> was moved from urb_enqueue() to endpoint_reset(). USB core
> doesn't use URBs before enable_device() or address_device(),
> but it may call endpoint_reset() on ep0.
> 
> A more serious bug has been identified by Sashiko review bot.
> Transaction Error of Address Device may cause the slot to be
> reallocated and left in Enabled state, but the input context
> [ ... ]
> at the time of address_device() and enable_device() calls.
> 
> Fixes: e34900f46cd6 ("xhci: Reconfigure endpoint 0 max packet size only during endpoint reset")
> Fixes: af8e119f52e9 ("xhci: Fix Panther point NULL pointer deref at full-speed re-enumeration")
> Signed-off-by: Michal Pecio <michal.pecio@gmail.com>

Sashiko has reviewed this patch and found no issues.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261109112846.04bfeb0f.michal.pecio@gmail.com?part=1