Re: [linus:master] [serial] 43066e3222: BUG:kernel_NULL_pointer_dereference,address

[Tony Lindgren]

* Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> [240404 14:34]:
> On Thu, Apr 04, 2024 at 09:54:15AM +0300, Tony Lindgren wrote:
> > * Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> [240403 14:00]:
> > > Probably we need to check if the port is still open...
> > > 
> > > P.S. AFAIU the state / xmit is invalid pointer or so.
> > > 
> > > Culprit line:	serial_out(up, UART_TX, xmit->buf[xmit->tail]);
> > 
> > Maybe we can set UPF_DEAD a bit earlier as below?
> 
> We should do this under port_mutex. Otherwise we replace one race by another.

Oh right.. And adding some better check in addition to UPF_DEAD
would be better.

Regards,

Tony