On Tue, Aug 2, 2016 at 9:31 PM, Doug Ledford <dledford@xxxxxxxxxx> wrote:
> On Sun, 2016-07-03 at 15:28 +0300, Leon Romanovsky wrote:
>> From: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>
>>
>> Fixes an oops that might happen if uverbs_close races with
>> remove_one.
>>
>> Both contexts may run ib_uverbs_cleanup_ucontext, it depends
>> on the flow.
>>
>> Currently, there is no protection for a case that remove_one
>> didn't make the cleanup it runs to its end, the underlying
>> ib_device was freed then uverbs_close will call
>> ib_uverbs_cleanup_ucontext and OOPs.
>>
>> Above might happen if uverbs_close deleted the file from the list
>> then remove_one didn't find it and runs to its end.
>>
>> Fixes to protect against that case by a new cleanup lock so that
>> ib_uverbs_cleanup_ucontext will be called always before that
>> remove_one is ended.
>>
>> Fixes: 35d4a0b63dc0 ("IB/uverbs: Fix race between ib_uverbs_open and
>> remove_one")
>> Reported-by: Devesh Sharma <devesh.sharma@xxxxxxxxxxxx>
>> Signed-off-by: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>
>> Signed-off-by: Yishai Hadas <yishaih@xxxxxxxxxxxx>
>> Signed-off-by: Leon Romanovsky <leon@xxxxxxxxxx>
>
> The only reason I hadn't taken this patch before is because Jason said
> it was totally untested and someone (Devesh in this case) needed to
> test it to make sure it resolved their problem. I don't see a test-by
> line here, so has this happened?
I can't say about Devesh, but we verified it as part of our verification phase.
Do you need anything special except Yishai's SOB?
>
> --
> Doug Ledford <dledford@xxxxxxxxxx>
> GPG KeyID: 0E572FDD
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