[PATCH] nvme-rdma: fix double free in nvme_rdma_free_queue

[PATCH] nvme-rdma: fix double free in nvme_rdma_free_queue

[Jianchao Wang]

BUG: KASAN: double-free or invalid-free in nvme_rdma_free_queue+0xf6/0x110 [nvme_rdma]
Workqueue: nvme-reset-wq nvme_rdma_reset_ctrl_work [nvme_rdma]
Call Trace:
 dump_stack+0x91/0xeb
 print_address_description+0x6b/0x290
 kasan_report_invalid_free+0x55/0x80
 __kasan_slab_free+0x176/0x190
 kfree+0xeb/0x310
 nvme_rdma_free_queue+0xf6/0x110 [nvme_rdma]
 nvme_rdma_configure_admin_queue+0x1a3/0x4d0 [nvme_rdma]
 nvme_rdma_reset_ctrl_work+0x4e/0xd0 [nvme_rdma]
 process_one_work+0x3ca/0xaa0
 worker_thread+0x4e2/0x6c0
 kthread+0x18d/0x1e0
 ret_from_fork+0x24/0x30

The double free is on ctrl->async_event_sqe.
If nvme_rdma_start_queue in nvme_rdma_configure_admin_queue fails,
nvme_rdma_free_queue will be invoked. However, at the moment, the
ctrl->async_event_sqe has not been allocated and it has been freed
in
nvme_rdma_reset_ctrl_work
  -> nvme_rdma_shutdown_ctrl
    ->nvme_rdma_destroy_admin_queue
      -> nvme_rdma_free_queue

Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com>
---
 drivers/nvme/host/rdma.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index a0ead1d..fd965d0 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -168,8 +168,11 @@ static inline size_t nvme_rdma_inline_data_size(struct nvme_rdma_queue *queue)
 static void nvme_rdma_free_qe(struct ib_device *ibdev, struct nvme_rdma_qe *qe,
 		size_t capsule_size, enum dma_data_direction dir)
 {
+	if (!qe->data)
+		return;
 	ib_dma_unmap_single(ibdev, qe->dma, capsule_size, dir);
 	kfree(qe->data);
+	qe->data = NULL;
 }
 
 static int nvme_rdma_alloc_qe(struct ib_device *ibdev, struct nvme_rdma_qe *qe,
-- 
2.7.4

Re: [PATCH] nvme-rdma: fix double free in nvme_rdma_free_queue

[Johannes Thumshirn]

Looks good,
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
-- 
Johannes Thumshirn                                          Storage
jthumshirn@suse.de                                +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850

Re: [PATCH] nvme-rdma: fix double free in nvme_rdma_free_queue

[Christoph Hellwig]

On Fri, May 04, 2018 at 04:02:18PM +0800, Jianchao Wang wrote:
> BUG: KASAN: double-free or invalid-free in nvme_rdma_free_queue+0xf6/0x110 [nvme_rdma]
> Workqueue: nvme-reset-wq nvme_rdma_reset_ctrl_work [nvme_rdma]
> Call Trace:
>  dump_stack+0x91/0xeb
>  print_address_description+0x6b/0x290
>  kasan_report_invalid_free+0x55/0x80
>  __kasan_slab_free+0x176/0x190
>  kfree+0xeb/0x310
>  nvme_rdma_free_queue+0xf6/0x110 [nvme_rdma]
>  nvme_rdma_configure_admin_queue+0x1a3/0x4d0 [nvme_rdma]
>  nvme_rdma_reset_ctrl_work+0x4e/0xd0 [nvme_rdma]
>  process_one_work+0x3ca/0xaa0
>  worker_thread+0x4e2/0x6c0
>  kthread+0x18d/0x1e0
>  ret_from_fork+0x24/0x30
> 
> The double free is on ctrl->async_event_sqe.
> If nvme_rdma_start_queue in nvme_rdma_configure_admin_queue fails,
> nvme_rdma_free_queue will be invoked. However, at the moment, the
> ctrl->async_event_sqe has not been allocated and it has been freed
> in
> nvme_rdma_reset_ctrl_work
>   -> nvme_rdma_shutdown_ctrl
>     ->nvme_rdma_destroy_admin_queue
>       -> nvme_rdma_free_queue
> 
> Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com>

Can you handle this in the caller instead, maybe including a comment?

Re: [PATCH] nvme-rdma: fix double free in nvme_rdma_free_queue

[jianchao.wang]

Hi Christoph

On 05/07/2018 08:27 PM, Christoph Hellwig wrote:
> On Fri, May 04, 2018 at 04:02:18PM +0800, Jianchao Wang wrote:
>> BUG: KASAN: double-free or invalid-free in nvme_rdma_free_queue+0xf6/0x110 [nvme_rdma]
>> Workqueue: nvme-reset-wq nvme_rdma_reset_ctrl_work [nvme_rdma]
>> Call Trace:
>>  dump_stack+0x91/0xeb
>>  print_address_description+0x6b/0x290
>>  kasan_report_invalid_free+0x55/0x80
>>  __kasan_slab_free+0x176/0x190
>>  kfree+0xeb/0x310
>>  nvme_rdma_free_queue+0xf6/0x110 [nvme_rdma]
>>  nvme_rdma_configure_admin_queue+0x1a3/0x4d0 [nvme_rdma]
>>  nvme_rdma_reset_ctrl_work+0x4e/0xd0 [nvme_rdma]
>>  process_one_work+0x3ca/0xaa0
>>  worker_thread+0x4e2/0x6c0
>>  kthread+0x18d/0x1e0
>>  ret_from_fork+0x24/0x30
>>
>> The double free is on ctrl->async_event_sqe.
>> If nvme_rdma_start_queue in nvme_rdma_configure_admin_queue fails,
>> nvme_rdma_free_queue will be invoked. However, at the moment, the
>> ctrl->async_event_sqe has not been allocated and it has been freed
>> in
>> nvme_rdma_reset_ctrl_work
>>   -> nvme_rdma_shutdown_ctrl
>>     ->nvme_rdma_destroy_admin_queue
>>       -> nvme_rdma_free_queue
>>
>> Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com>
> 
> Can you handle this in the caller instead, maybe including a comment?
> 
Yes, that will be clearer.
Thanks for your suggestion.

Jianchao