cvs commit: src/sys/dev/usb umass.c

Scott Long scottl at samsco.org
Mon Mar 6 15:51:55 PST 2006


M. Warner Losh wrote:
> In message: <440B41DF.1010305 at root.org>
>             Nate Lawson <nate at root.org> writes:
> : Poul-Henning Kamp wrote:
> : > phk         2006-03-05 17:52:32 UTC
> : > 
> : >   FreeBSD src repository
> : > 
> : >   Modified files:
> : >     sys/dev/usb          umass.c 
> : >   Log:
> : >   When we get an unknown ATAPI comand, try it even if it is not listed,
> : >   in all likelyhood just passing it through will work.
> : >   
> : >   Revision  Changes    Path
> : >   1.134     +4 -2      src/sys/dev/usb/umass.c
> : 
> : Given that most umass devices can't even handle the commands required by 
> : the spec (RBC), this seems dangerous.  Still, might be worth trying in 
> : HEAD just to see what commands it needs to support.
> 
> It depends on the umass device.  The thumb drives are universally
> stupid and fragile.  This change is dangerous for them (although why
> one would send arbitrary commands to them I know not).  There are a
> number of usb2 to PATA or SATA that this fix is the right thing to do,
> since for those it is required to get things like cdrecord to run w/o
> complaint.
> 
> Warner

What would likely have been safer, and I meant to discuss this with PHJK 
but forgot, is to only pass commands that are 10 bytes long, and
summarily reject all others.

Scott


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