Re: [PATCH] w1_therm reference count family data

From: Evgeniy Polyakov
Date: Wed May 13 2015 - 11:00:03 EST


Hi

09.05.2015, 03:52, "David Fries" <David@xxxxxxxxx>:
> A temperature conversion can take 750 ms and when possible the
> w1_therm slave driver drops the bus_mutex to allow other bus
> operations, but that includes operations such as a periodic slave
> search, which can remove this slave when it is no longer detected.
> If that happens the sl->family_data will be freed and set to NULL
> causing w1_slave_show to crash when it wakes up.
>
> Signed-off-by: David Fries <David@xxxxxxxxx>
> Reported-By: Thorsten Bschorr <thorsten@xxxxxxxxxx>
> Tested-by: Thorsten Bschorr <thorsten@xxxxxxxxxx>
> Acked-by: Evgeniy Polyakov <zbr@xxxxxxxxxxx>
> ---
> This should be applied to the stable series as well.  In the name of
> full disclosure, this just narrows the race window, from crashing in
> normal operation on the reporters system to no longer crashing with
> multiple readers and another process hammering on inserting/removing
> the slave device.

Greg, please pull it upstream
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