* [PATCH v2] nvme-pci: fix dbbuf_sq_db point to freed memory
@ 2018-12-21 1:07 ` Lulina (A)
0 siblings, 0 replies; 6+ messages in thread
From: Lulina (A) @ 2018-12-21 1:07 UTC (permalink / raw)
To: axboe, hch; +Cc: linux-nvme, linux-kernel
The case is that nvme device support NVME_CTRL_OACS_DBBUF_SUPP, and
return failed when the driver sent nvme_admin_dbbuf. The nvmeq->dbbuf_sq_db
point to freed memory, as nvme_dbbuf_set is called after nvme_dbbuf_init.
Signed-off-by: lulina <lina.lulina@huawei.com>
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index c33bb20..a477905 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -251,16 +251,25 @@ static int nvme_dbbuf_dma_alloc(struct nvme_dev *dev)
static void nvme_dbbuf_dma_free(struct nvme_dev *dev)
{
unsigned int mem_size = nvme_dbbuf_size(dev->db_stride);
+ unsigned int i;
if (dev->dbbuf_dbs) {
dma_free_coherent(dev->dev, mem_size,
dev->dbbuf_dbs, dev->dbbuf_dbs_dma_addr);
dev->dbbuf_dbs = NULL;
+ for (i = dev->ctrl.queue_count - 1; i > 0; i--) {
+ dev->queues[i].dbbuf_sq_db = NULL;
+ dev->queues[i].dbbuf_cq_db = NULL;
+ }
}
if (dev->dbbuf_eis) {
dma_free_coherent(dev->dev, mem_size,
dev->dbbuf_eis, dev->dbbuf_eis_dma_addr);
dev->dbbuf_eis = NULL;
+ for (i = dev->ctrl.queue_count - 1; i > 0; i--) {
+ dev->queues[i].dbbuf_sq_ei = NULL;
+ dev->queues[i].dbbuf_cq_ei = NULL;
+ }
}
}
--
1.8.3.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v2] nvme-pci: fix dbbuf_sq_db point to freed memory
@ 2018-12-21 1:07 ` Lulina (A)
0 siblings, 0 replies; 6+ messages in thread
From: Lulina (A) @ 2018-12-21 1:07 UTC (permalink / raw)
The case is that nvme device support NVME_CTRL_OACS_DBBUF_SUPP, and
return failed when the driver sent nvme_admin_dbbuf. The nvmeq->dbbuf_sq_db
point to freed memory, as nvme_dbbuf_set is called after nvme_dbbuf_init.
Signed-off-by: lulina <lina.lulina at huawei.com>
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index c33bb20..a477905 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -251,16 +251,25 @@ static int nvme_dbbuf_dma_alloc(struct nvme_dev *dev)
static void nvme_dbbuf_dma_free(struct nvme_dev *dev)
{
unsigned int mem_size = nvme_dbbuf_size(dev->db_stride);
+ unsigned int i;
if (dev->dbbuf_dbs) {
dma_free_coherent(dev->dev, mem_size,
dev->dbbuf_dbs, dev->dbbuf_dbs_dma_addr);
dev->dbbuf_dbs = NULL;
+ for (i = dev->ctrl.queue_count - 1; i > 0; i--) {
+ dev->queues[i].dbbuf_sq_db = NULL;
+ dev->queues[i].dbbuf_cq_db = NULL;
+ }
}
if (dev->dbbuf_eis) {
dma_free_coherent(dev->dev, mem_size,
dev->dbbuf_eis, dev->dbbuf_eis_dma_addr);
dev->dbbuf_eis = NULL;
+ for (i = dev->ctrl.queue_count - 1; i > 0; i--) {
+ dev->queues[i].dbbuf_sq_ei = NULL;
+ dev->queues[i].dbbuf_cq_ei = NULL;
+ }
}
}
--
1.8.3.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v2] nvme-pci: fix dbbuf_sq_db point to freed memory
2018-12-21 1:07 ` Lulina (A)
@ 2019-01-04 18:07 ` Christoph Hellwig
-1 siblings, 0 replies; 6+ messages in thread
From: Christoph Hellwig @ 2019-01-04 18:07 UTC (permalink / raw)
To: Lulina (A); +Cc: axboe, hch, linux-kernel, linux-nvme
On Fri, Dec 21, 2018 at 01:07:25AM +0000, Lulina (A) wrote:
> The case is that nvme device support NVME_CTRL_OACS_DBBUF_SUPP, and
> return failed when the driver sent nvme_admin_dbbuf. The nvmeq->dbbuf_sq_db
> point to freed memory, as nvme_dbbuf_set is called after nvme_dbbuf_init.
But we never use those pointers in that state, do we? Can you explain
the problem in a little more detail?
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v2] nvme-pci: fix dbbuf_sq_db point to freed memory
@ 2019-01-04 18:07 ` Christoph Hellwig
0 siblings, 0 replies; 6+ messages in thread
From: Christoph Hellwig @ 2019-01-04 18:07 UTC (permalink / raw)
On Fri, Dec 21, 2018@01:07:25AM +0000, Lulina (A) wrote:
> The case is that nvme device support NVME_CTRL_OACS_DBBUF_SUPP, and
> return failed when the driver sent nvme_admin_dbbuf. The nvmeq->dbbuf_sq_db
> point to freed memory, as nvme_dbbuf_set is called after nvme_dbbuf_init.
But we never use those pointers in that state, do we? Can you explain
the problem in a little more detail?
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] nvme-pci: fix dbbuf_sq_db point to freed memory
2019-01-04 18:07 ` Christoph Hellwig
@ 2019-01-07 5:27 ` Lulina (A)
-1 siblings, 0 replies; 6+ messages in thread
From: Lulina (A) @ 2019-01-07 5:27 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: axboe, hch, linux-kernel, linux-nvme
Thanks for replying to my email, my description in the last email was not
clear enough, so here's a supplementary note.
The NVME device I used support DBBUF, but the nvme_admin_dbbuf request
returned a failure that eventually led to the kernel crash.
The problem occurs as follows:
1, Device support NVME_CTRL_OACS_DBBUF_SUPP，so reset worker alloc memory
for dev->dbbuf_dbs。
2, In nvme_setup_io_queues process, the nvme_dbbuf_init function is called
to assign values to pointers such as nvmeq->dbbuf_sq_db.
3, In nvme_dev_add function, the nvme_admin_dbbuf request is sent to the
device, but the device returns failed, so the memory that dev->dbbuf_dbs
points to is released.
Then, the driver issued IO requests, in the nvme_write_sq_db process,
nvme_dbbuf_update_and_check_event function judgment to Nvmeq->dbbuf_sq_db
pointer is not NULL, write to the memory it points to, causing memory
confusion and kernel crash.
On 2019/1/5 2:07, Christoph Hellwig wrote:
> On Fri, Dec 21, 2018 at 01:07:25AM +0000, Lulina (A) wrote:
>> The case is that nvme device support NVME_CTRL_OACS_DBBUF_SUPP, and
>> return failed when the driver sent nvme_admin_dbbuf. The nvmeq->dbbuf_sq_db
>> point to freed memory, as nvme_dbbuf_set is called after nvme_dbbuf_init.
>
> But we never use those pointers in that state, do we? Can you explain
> the problem in a little more detail?
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v2] nvme-pci: fix dbbuf_sq_db point to freed memory
@ 2019-01-07 5:27 ` Lulina (A)
0 siblings, 0 replies; 6+ messages in thread
From: Lulina (A) @ 2019-01-07 5:27 UTC (permalink / raw)
Thanks for replying to my email, my description in the last email was not
clear enough, so here's a supplementary note.
The NVME device I used support DBBUF, but the nvme_admin_dbbuf request
returned a failure that eventually led to the kernel crash.
The problem occurs as follows:
1, Device support NVME_CTRL_OACS_DBBUF_SUPP?so reset worker alloc memory
for dev->dbbuf_dbs?
2, In nvme_setup_io_queues process, the nvme_dbbuf_init function is called
to assign values to pointers such as nvmeq->dbbuf_sq_db.
3, In nvme_dev_add function, the nvme_admin_dbbuf request is sent to the
device, but the device returns failed, so the memory that dev->dbbuf_dbs
points to is released.
Then, the driver issued IO requests, in the nvme_write_sq_db process,
nvme_dbbuf_update_and_check_event function judgment to Nvmeq->dbbuf_sq_db
pointer is not NULL, write to the memory it points to, causing memory
confusion and kernel crash.
On 2019/1/5 2:07, Christoph Hellwig wrote:
> On Fri, Dec 21, 2018@01:07:25AM +0000, Lulina (A) wrote:
>> The case is that nvme device support NVME_CTRL_OACS_DBBUF_SUPP, and
>> return failed when the driver sent nvme_admin_dbbuf. The nvmeq->dbbuf_sq_db
>> point to freed memory, as nvme_dbbuf_set is called after nvme_dbbuf_init.
>
> But we never use those pointers in that state, do we? Can you explain
> the problem in a little more detail?
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2019-01-07 5:28 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-12-21 1:07 [PATCH v2] nvme-pci: fix dbbuf_sq_db point to freed memory Lulina (A)
2018-12-21 1:07 ` Lulina (A)
2019-01-04 18:07 ` Christoph Hellwig
2019-01-04 18:07 ` Christoph Hellwig
2019-01-07 5:27 ` Lulina (A)
2019-01-07 5:27 ` Lulina (A)
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