Re: [PATCH] xhci: Free the command allocated for setting LPM if we return early

From: Mirsad Goran Todorovac
Date: Mon Mar 27 2023 - 18:25:50 EST


On 27. 03. 2023. 11:50, Mathias Nyman wrote:
> The command allocated to set exit latency LPM values need to be freed in
> case the command is never queued. This would be the case if there is no
> change in exit latency values, or device is missing.
>
> Fixes: 5c2a380a5aa8 ("xhci: Allocate separate command structures for each LPM command")
> Cc: <Stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/host/xhci.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index bdb6dd819a3b..6307bae9cddf 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -4442,6 +4442,7 @@ static int __maybe_unused xhci_change_max_exit_latency(struct xhci_hcd *xhci,
>
> if (!virt_dev || max_exit_latency == virt_dev->current_mel) {
> spin_unlock_irqrestore(&xhci->lock, flags);
> + xhci_free_command(xhci, command);
> return 0;
> }
>

After more testing, I can confirm that your patch fixes the leak in the original
environment.

And I see that you independently already have bisected the culprit commit, so I
have needlessly duplicated the work.

However, I consider myself still a learner and an absolute beginner in the Linux
kernel world ...

Best regards,
Mirsad

--
Mirsad Goran Todorovac
Sistem inženjer
Grafički fakultet | Akademija likovnih umjetnosti
Sveučilište u Zagrebu

System engineer
Faculty of Graphic Arts | Academy of Fine Arts
University of Zagreb, Republic of Croatia
The European Union

"I see something approaching fast ... Will it be friends with me?"