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

[Greg Kroah-Hartman]

On Wed, Apr 17, 2024 at 08:24:13AM -0400, Parker Newman wrote:
> On Wed, 17 Apr 2024 13:19:07 +0200
> Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> 
> > On Tue, Apr 16, 2024 at 08:55:35AM -0400, Parker Newman wrote:
> > > From: Parker Newman <pnewman@xxxxxxxxxxxxxxx>
> > >
> > > 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@xxxxxxxxxxxxxxx>
> > > ---
> > >  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.

Great!  Bonus points if you can find the commit id it fixes and add a
"Fixes:" tag to the signed-off-by area.  If not, I can guess :)

thanks,

greg k-h