On 5/31/2018 4:21 PM, Jason Gunthorpe wrote:
On Thu, May 31, 2018 at 03:08:56PM -0400, Dennis Dalessandro wrote:
On 5/31/2018 2:47 PM, Doug Ledford wrote:
On Thu, 2018-05-31 at 11:29 -0700, Dennis Dalessandro wrote:
Hi Doug and Jason,
We have two more late breaking fix up patches. The DMA_RTAIL fix is the more serious of the two. I realize we are at the tail end of 4.17 so I would not be against holding off till 4.18 for these, but if there is another rdma pull request we may want to tack these on.
Kaike Wan (1): IB/hfi1: Ensure VL index is within bounds
Mike Marciniszyn (1): IB/hfi1: Fix user context tail allocation for DMA_RTAIL
drivers/infiniband/hw/hfi1/chip.c | 8 ++++---- drivers/infiniband/hw/hfi1/file_ops.c | 2 +- drivers/infiniband/hw/hfi1/init.c | 9 ++++----- drivers/infiniband/hw/hfi1/sdma.c | 12 +++--------- 4 files changed, 12 insertions(+), 19 deletions(-)
Hi Denny,
These two patches look fine in terms of the patches themselves. In terms of whether to put them in for-rc or for-next, what's the consequences of hitting each of these bugs?
The VL index, could be bad because it would jump beyond the end of the array. However, we won't actually hit that with the code the way it currently is because of the way we validate the VL in other areas of the code. This is more of a we better fix it before we do end up with a problem sort of thing.
Theoretical future bugs are not rc or stable material
The VL index one is not marked as stable, however the other one is. That is because it is a real bug, as Mike said to me earlier, we provide the tools to play, the concern is if someone does. So I think it meets stable bar, but not necessarily this late of an -rc.
In the other one, the DMA_RTAIL one, the driver ends up mmaping NULL and handing that user space. This only happens though if users muck with the CAP_MASK and enable the dma of the rtail. Which is not the default. Mike found this through code inspection I believe.
So they do fix serious flaws, but the likelihood of actually hitting them is very slim. Based on the stable tag on Mike's patch we have had this since 4.9.
I think it is too late for more -rc stuff..
The last -rc (assuming rc7 is the end) pull request needs to go tomorrow morning and we like it to have -rc stuff sit in -next for at least a day before sending to Linus :\
Agree, and fine with me.
-Denny