4.16-stable review patch. If anyone has any objections, please let me know.
------------------
From: Michael J. Ruhl michael.j.ruhl@intel.com
commit f9e76ca3771bf23d2142a81a88ddd8f31f5c4c03 upstream.
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@vger.kernel.org # 4.9.x Reviewed-by: Mike Marciniszyn mike.marciniszyn@intel.com Reviewed-by: Dennis Dalessandro dennis.dalessandro@intel.com Signed-off-by: Michael J. Ruhl michael.j.ruhl@intel.com Signed-off-by: Dennis Dalessandro dennis.dalessandro@intel.com Signed-off-by: Doug Ledford dledford@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/infiniband/hw/hfi1/chip.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/drivers/infiniband/hw/hfi1/chip.c +++ b/drivers/infiniband/hw/hfi1/chip.c @@ -5944,6 +5944,7 @@ static void is_sendctxt_err_int(struct h u64 status; u32 sw_index; int i = 0; + unsigned long irq_flags;
sw_index = dd->hw_to_sw[hw_context]; if (sw_index >= dd->num_send_contexts) { @@ -5953,10 +5954,12 @@ static void is_sendctxt_err_int(struct h return; } sci = &dd->send_contexts[sw_index]; + spin_lock_irqsave(&dd->sc_lock, irq_flags); sc = sci->sc; if (!sc) { dd_dev_err(dd, "%s: context %u(%u): no sc?\n", __func__, sw_index, hw_context); + spin_unlock_irqrestore(&dd->sc_lock, irq_flags); return; }
@@ -5978,6 +5981,7 @@ static void is_sendctxt_err_int(struct h */ if (sc->type != SC_USER) queue_work(dd->pport->hfi1_wq, &sc->halt_work); + spin_unlock_irqrestore(&dd->sc_lock, irq_flags);
/* * Update the counters for the corresponding status bits.