[vbox-dev] Nullpointer access by USBDevIo thread in vusbUrbDoReapAsync

Alexander Boettcher alexander.boettcher at genode-labs.com
Tue Feb 13 10:45:01 UTC 2018


we encountered in our ported version of Virtualbox (originally in
5.1.22, now in 5.1.32) from time to time a nullpointer crash in the
context of the USBDevIo thread (vusbUrbDoReapAsync() function).

We get around by the following patch [1] (original bug report at [2])
and all seems to work as expected.

The question from my side is, do you think this is valid fix ? Or do you
expect that pVUsbUrbNext should never be null and it maybe just becomes
null possibly due to our porting (timing, wrong usage etc.) ?

After looking through your svn repository at [0] it seems the issue also
could possibly exists there, since the code looks very similar regarding
the pVUsbUrbNext variable compared to 5.1.22/32.

Thanks for any thoughts,

Alexander Boettcher.

[2] https://github.com/genodelabs/genode/issues/2612

Alexander Boettcher
Genode Labs

http://www.genode-labs.com - http://www.genode.org

Genode Labs GmbH - Amtsgericht Dresden - HRB 28424 - Sitz Dresden
Geschäftsführer: Dr.-Ing. Norman Feske, Christian Helmuth

More information about the vbox-dev mailing list