Re: [PATCH v3 8/8] serial: exar: fix: fix crash during shutdown if setup fails

[Parker Newman <parker@finest.io>]

On Wed, 17 Apr 2024 13:19:07 +0200
Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:

> On Tue, Apr 16, 2024 at 08:55:35AM -0400, Parker Newman wrote:
> > From: Parker Newman <pnewman@connecttech.com>
> >
> > If a port fails to register with serial8250_register_8250_port() the
> > kernel can crash when shutting down or module removal.
> >
> > This is because "priv->line[i]" will be set to a negative error code
> > and in the exar_pci_remove() function serial8250_unregister_port() is
> > called without checking if the "priv->line[i]" value is valid.
> >
> > Signed-off-by: Parker Newman <pnewman@connecttech.com>
> > ---
> >  drivers/tty/serial/8250/8250_exar.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
> > index 501b9f3e9c89..f5a395ed69d1 100644
> > --- a/drivers/tty/serial/8250/8250_exar.c
> > +++ b/drivers/tty/serial/8250/8250_exar.c
> > @@ -1671,7 +1671,8 @@ static void exar_pci_remove(struct pci_dev *pcidev)
> >  	unsigned int i;
> >
> >  	for (i = 0; i < priv->nr; i++)
> > -		serial8250_unregister_port(priv->line[i]);
> > +		if (priv->line[i] >= 0)
> > +			serial8250_unregister_port(priv->line[i]);
>
> Is this a bug in the current driver?  If so, can you resend it on its
> own so we can get it merged now?
>

Yes it is, I can split this one out and send it on its own.
Thanks,
Parker

> thanks,
>
> greg k-h