On 5/4/2018 2:38 PM, Jason Gunthorpe wrote:
On Wed, May 02, 2018 at 06:42:51AM -0700, Dennis Dalessandro wrote:
From: Michael J. Ruhl <michael.j.ruhl@xxxxxxxxx>
A pio send egress error can occur when the PSM library attempts to
to send a bad packet. That issue is still being investigated.
The pio error interrupt handler then attempts to progress the recovery
of the errored pio send context.
Code inspection reveals that the handling lacks the necessary locking
if that recovery interleaves with a PSM close of the "context" object
contains the pio send context.
The lack of the locking can cause the recovery to access the already
freed pio send context object and incorrectly deduce that the pio
send context is actually a kernel pio send context as shown by the
NULL deref stack below:
[<ffffffff8143d78c>] _dev_info+0x6c/0x90
[<ffffffffc0613230>] sc_restart+0x70/0x1f0 [hfi1]
[<ffffffff816ab124>] ? __schedule+0x424/0x9b0
[<ffffffffc06133c5>] sc_halted+0x15/0x20 [hfi1]
[<ffffffff810aa3ba>] process_one_work+0x17a/0x440
[<ffffffff810ab086>] worker_thread+0x126/0x3c0
[<ffffffff810aaf60>] ? manage_workers.isra.24+0x2a0/0x2a0
[<ffffffff810b252f>] kthread+0xcf/0xe0
[<ffffffff810b2460>] ? insert_kthread_work+0x40/0x40
[<ffffffff816b8798>] ret_from_fork+0x58/0x90
[<ffffffff810b2460>] ? insert_kthread_work+0x40/0x40
This is the best case scenario and other scenarios can corrupt the
already freed memory.
Fix by adding the necessary locking in the pio send context error
handler.
Cc: <stable@xxxxxxxxxxxxxxx> # 4.9.x
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@xxxxxxxxx>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
---
drivers/infiniband/hw/hfi1/chip.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
Why are you sending this to for-next not for-rc?
I went back and forth on this one. In the end decided against it because
we've lived with it for so long, note stable tag is all the way back to
4.9, that and the fact that it's extremely unlikely to occur. I would be
fine including it with the -rc though. I think a case could be made
either way.
-Denny
