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From: Dennis Dalessandro <>
	"Michael J. Ruhl" <>,
	Mike Marciniszyn <>,
Subject: [PATCH for-next 05/14] IB/hfi1: Use after free race condition in send context error path
Date: Wed, 02 May 2018 06:42:51 -0700	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

From: Michael J. Ruhl <>

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

Cc: <> # 4.9.x
Reviewed-by: Mike Marciniszyn <>
Reviewed-by: Dennis Dalessandro <>
Signed-off-by: Michael J. Ruhl <>
Signed-off-by: Dennis Dalessandro <>
 drivers/infiniband/hw/hfi1/chip.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/chip.c b/drivers/infiniband/hw/hfi1/chip.c
index cb9095d..e5254f8 100644
--- 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 hfi1_devdata *dd,
 	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 hfi1_devdata *dd,
 	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);
@@ -5978,6 +5981,7 @@ static void is_sendctxt_err_int(struct hfi1_devdata *dd,
 	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.

  parent reply	other threads:[~2018-05-02 13:42 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-02 13:42 [PATCH for-next 00/14] IB/hfi1: Updates for-next 5/2/2018 Dennis Dalessandro
2018-05-02 13:42 ` Dennis Dalessandro
2018-05-02 13:42 ` [PATCH for-next 04/14] IB/hfi1: Fix fault injection init/exit issues Dennis Dalessandro
2018-05-02 13:42 ` Dennis Dalessandro [this message]
2018-05-04 18:38   ` [PATCH for-next 05/14] IB/hfi1: Use after free race condition in send context error path Jason Gunthorpe
2018-05-04 20:01     ` Dennis Dalessandro
2018-05-09 14:38       ` Doug Ledford
2018-05-02 13:43 ` [PATCH for-next 07/14] IB/hfi1: Reorder incorrect send context disable Dennis Dalessandro
2018-05-02 13:43 ` [PATCH for-next 08/14] IB/{hfi1, qib}: Add handling of kernel restart Dennis Dalessandro
2018-05-02 13:43 ` [PATCH for-next 11/14] IB/hfi1: Optimize kthread pointer locking when queuing CQ entries Dennis Dalessandro
2018-05-15 14:35 ` [PATCH for-next 00/14] IB/hfi1: Updates for-next 5/2/2018 Doug Ledford

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