On 2/12/21 10:49 PM, Sagi Grimberg wrote:
blk_mq_tag_to_rq() will always return a request if the command_id is
in the valid range. Check if the request has been started. If we
blindly process the request we might double complete a request which
can be fatal.
How did you get to this one? did the controller send a completion for
a completed/bogus request?
If that is the case, then that must mean it's possible the driver could
have started the command id just before the bogus completion check. Data
iorruption, right?
Yes, which is why I don't think this check is very useful..
I actually view that as a valid protection against spoofed frames.
Without it it's easy to crash the machine by injecting fake completions
with random command ids.
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
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