Re: [PATCH AUTOSEL 5.4 041/330] USB: serial: mos7840: fix probe error handling

From: Sasha Levin
Date: Thu Sep 24 2020 - 16:54:19 EST


On Fri, Sep 18, 2020 at 08:53:00AM +0200, Johan Hovold wrote:
On Thu, Sep 17, 2020 at 09:56:21PM -0400, Sasha Levin wrote:
From: Johan Hovold <johan@xxxxxxxxxx>

[ Upstream commit 960fbd1ca584a5b4cd818255769769d42bfc6dbe ]

The driver would return success and leave the port structures
half-initialised if any of the register accesses during probe fails.

This would specifically leave the port control urb unallocated,
something which could trigger a NULL pointer dereference on interrupt
events.

Fortunately the interrupt implementation is completely broken and has
never even been enabled...

Note that the zero-length-enable register write used to set the zle-flag
for all ports is moved to attach.

Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

Please drop this from all stable queues. As the commit message and
missing stable-cc tag suggests, it's not needed.

Sasha, please stop sending AUTOSEL patches for usb-serial. I think this
the fourth time I ask you now.

Right, this series is a bit different because it didn't originate from
the AUTOSEL work but rather was an audit of patches picked up by
downstream kernels as fixes.

I'll drop it, sorry for the noise.

--
Thanks,
Sasha