[PATCH] infiniband: Fix a use after free in isert_connect_request

[PATCH] infiniband: Fix a use after free in isert_connect_request

[Lv Yunlong]

The device is got by isert_device_get() with refcount is 1,
and is assigned to isert_conn by isert_conn->device = device.
When isert_create_qp() failed, device will be freed with
isert_device_put().

Later, the device is used in isert_free_login_buf(isert_conn)
by the isert_conn->device->ib_device statement. My patch
exchanges the callees order to free the device late.

Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
---
 drivers/infiniband/ulp/isert/ib_isert.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index 7305ed8976c2..d8a533e346b0 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -473,10 +473,10 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
 
 out_destroy_qp:
 	isert_destroy_qp(isert_conn);
-out_conn_dev:
-	isert_device_put(device);
 out_rsp_dma_map:
 	isert_free_login_buf(isert_conn);
+out_conn_dev:
+	isert_device_put(device);
 out:
 	kfree(isert_conn);
 	rdma_reject(cma_id, NULL, 0, IB_CM_REJ_CONSUMER_DEFINED);
-- 
2.25.1

Re: [PATCH] infiniband: Fix a use after free in isert_connect_request

[Leon Romanovsky]

On Mon, Mar 22, 2021 at 06:53:55AM -0700, Lv Yunlong wrote:
> The device is got by isert_device_get() with refcount is 1,
> and is assigned to isert_conn by isert_conn->device = device.
> When isert_create_qp() failed, device will be freed with
> isert_device_put().
> 
> Later, the device is used in isert_free_login_buf(isert_conn)
> by the isert_conn->device->ib_device statement. My patch
> exchanges the callees order to free the device late.
> 
> Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
> ---
>  drivers/infiniband/ulp/isert/ib_isert.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

The fix needs to be change of isert_free_login_buf() from
isert_free_login_buf(isert_conn) to be isert_free_login_buf(isert_conn, cma_id->device)

Thanks

> 
> diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
> index 7305ed8976c2..d8a533e346b0 100644
> --- a/drivers/infiniband/ulp/isert/ib_isert.c
> +++ b/drivers/infiniband/ulp/isert/ib_isert.c
> @@ -473,10 +473,10 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
>  
>  out_destroy_qp:
>  	isert_destroy_qp(isert_conn);
> -out_conn_dev:
> -	isert_device_put(device);
>  out_rsp_dma_map:
>  	isert_free_login_buf(isert_conn);
> +out_conn_dev:
> +	isert_device_put(device);
>  out:
>  	kfree(isert_conn);
>  	rdma_reject(cma_id, NULL, 0, IB_CM_REJ_CONSUMER_DEFINED);
> -- 
> 2.25.1
> 
> 

Re: Re: [PATCH] infiniband: Fix a use after free in isert_connect_request

[lyl2019]

> -----原始邮件-----
> 发件人: "Leon Romanovsky" <leon@kernel.org>
> 发送时间: 2021-03-22 22:27:17 (星期一)
> 收件人: "Lv Yunlong" <lyl2019@mail.ustc.edu.cn>
> 抄送: sagi@grimberg.me, dledford@redhat.com, jgg@ziepe.ca, linux-rdma@vger.kernel.org, target-devel@vger.kernel.org, linux-kernel@vger.kernel.org
> 主题: Re: [PATCH] infiniband: Fix a use after free in isert_connect_request
> 
> On Mon, Mar 22, 2021 at 06:53:55AM -0700, Lv Yunlong wrote:
> > The device is got by isert_device_get() with refcount is 1,
> > and is assigned to isert_conn by isert_conn->device = device.
> > When isert_create_qp() failed, device will be freed with
> > isert_device_put().
> > 
> > Later, the device is used in isert_free_login_buf(isert_conn)
> > by the isert_conn->device->ib_device statement. My patch
> > exchanges the callees order to free the device late.
> > 
> > Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
> > ---
> >  drivers/infiniband/ulp/isert/ib_isert.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> The fix needs to be change of isert_free_login_buf() from
> isert_free_login_buf(isert_conn) to be isert_free_login_buf(isert_conn, cma_id->device)
> 
> Thanks
> 
> > 
> > diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
> > index 7305ed8976c2..d8a533e346b0 100644
> > --- a/drivers/infiniband/ulp/isert/ib_isert.c
> > +++ b/drivers/infiniband/ulp/isert/ib_isert.c
> > @@ -473,10 +473,10 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
> >  
> >  out_destroy_qp:
> >  	isert_destroy_qp(isert_conn);
> > -out_conn_dev:
> > -	isert_device_put(device);
> >  out_rsp_dma_map:
> >  	isert_free_login_buf(isert_conn);
> > +out_conn_dev:
> > +	isert_device_put(device);
> >  out:
> >  	kfree(isert_conn);
> >  	rdma_reject(cma_id, NULL, 0, IB_CM_REJ_CONSUMER_DEFINED);
> > -- 
> > 2.25.1
> > 
> > 

I see that function isert_free_login_buf(struct isert_conn *isert_conn) has only
a parameter,  do you mean i need change the implementation of isert_free_login_buf?

I'm sorry to say that i am unfamilar with this module and afraid of making more mistakes,
because this function is being called elsewhere as well.
Could you help me to fix this issue? Or just fix it and tell me your commit number?

Re: Re: [PATCH] infiniband: Fix a use after free in isert_connect_request

[Leon Romanovsky]

On Mon, Mar 22, 2021 at 10:51:35PM +0800, lyl2019@mail.ustc.edu.cn wrote:
> 
> 
> 
> > -----原始邮件-----
> > 发件人: "Leon Romanovsky" <leon@kernel.org>
> > 发送时间: 2021-03-22 22:27:17 (星期一)
> > 收件人: "Lv Yunlong" <lyl2019@mail.ustc.edu.cn>
> > 抄送: sagi@grimberg.me, dledford@redhat.com, jgg@ziepe.ca, linux-rdma@vger.kernel.org, target-devel@vger.kernel.org, linux-kernel@vger.kernel.org
> > 主题: Re: [PATCH] infiniband: Fix a use after free in isert_connect_request
> > 
> > On Mon, Mar 22, 2021 at 06:53:55AM -0700, Lv Yunlong wrote:
> > > The device is got by isert_device_get() with refcount is 1,
> > > and is assigned to isert_conn by isert_conn->device = device.
> > > When isert_create_qp() failed, device will be freed with
> > > isert_device_put().
> > > 
> > > Later, the device is used in isert_free_login_buf(isert_conn)
> > > by the isert_conn->device->ib_device statement. My patch
> > > exchanges the callees order to free the device late.
> > > 
> > > Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
> > > ---
> > >  drivers/infiniband/ulp/isert/ib_isert.c | 4 ++--
> > >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > The fix needs to be change of isert_free_login_buf() from
> > isert_free_login_buf(isert_conn) to be isert_free_login_buf(isert_conn, cma_id->device)
> > 
> > Thanks
> > 
> > > 
> > > diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
> > > index 7305ed8976c2..d8a533e346b0 100644
> > > --- a/drivers/infiniband/ulp/isert/ib_isert.c
> > > +++ b/drivers/infiniband/ulp/isert/ib_isert.c
> > > @@ -473,10 +473,10 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
> > >  
> > >  out_destroy_qp:
> > >  	isert_destroy_qp(isert_conn);
> > > -out_conn_dev:
> > > -	isert_device_put(device);
> > >  out_rsp_dma_map:
> > >  	isert_free_login_buf(isert_conn);
> > > +out_conn_dev:
> > > +	isert_device_put(device);
> > >  out:
> > >  	kfree(isert_conn);
> > >  	rdma_reject(cma_id, NULL, 0, IB_CM_REJ_CONSUMER_DEFINED);
> > > -- 
> > > 2.25.1
> > > 
> > > 
> 
> I see that function isert_free_login_buf(struct isert_conn *isert_conn) has only
> a parameter,  do you mean i need change the implementation of isert_free_login_buf?
> 
> I'm sorry to say that i am unfamilar with this module and afraid of making more mistakes,
> because this function is being called elsewhere as well.
> Could you help me to fix this issue? Or just fix it and tell me your commit number?

After checking how isert_connect_release() is implemented, it looks like
this will fix:

diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index 7305ed8976c2..18266f07c58d 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -438,23 +438,23 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
 	isert_init_conn(isert_conn);
 	isert_conn->cm_id = cma_id;
 
-	ret = isert_alloc_login_buf(isert_conn, cma_id->device);
-	if (ret)
-		goto out;
-
 	device = isert_device_get(cma_id);
 	if (IS_ERR(device)) {
 		ret = PTR_ERR(device);
-		goto out_rsp_dma_map;
+		goto out;
 	}
 	isert_conn->device = device;
 
+	ret = isert_alloc_login_buf(isert_conn, cma_id->device);
+	if (ret)
+		goto out_conn_dev;
+
 	isert_set_nego_params(isert_conn, &event->param.conn);
 
 	isert_conn->qp = isert_create_qp(isert_conn, cma_id);
 	if (IS_ERR(isert_conn->qp)) {
 		ret = PTR_ERR(isert_conn->qp);
-		goto out_conn_dev;
+		goto out_rsp_dma_map;
 	}
 
 	ret = isert_login_post_recv(isert_conn);
@@ -473,10 +473,10 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
 
 out_destroy_qp:
 	isert_destroy_qp(isert_conn);
-out_conn_dev:
-	isert_device_put(device);
 out_rsp_dma_map:
 	isert_free_login_buf(isert_conn);
+out_conn_dev:
+	isert_device_put(device);
 out:
 	kfree(isert_conn);
 	rdma_reject(cma_id, NULL, 0, IB_CM_REJ_CONSUMER_DEFINED);

Re: Re: Re: [PATCH] infiniband: Fix a use after free in isert_connect_request

[lyl2019]

> -----原始邮件-----
> 发件人: "Leon Romanovsky" <leon@kernel.org>
> 发送时间: 2021-03-22 23:31:08 (星期一)
> 收件人: lyl2019@mail.ustc.edu.cn
> 抄送: sagi@grimberg.me, dledford@redhat.com, jgg@ziepe.ca, linux-rdma@vger.kernel.org, target-devel@vger.kernel.org, linux-kernel@vger.kernel.org
> 主题: Re: Re: [PATCH] infiniband: Fix a use after free in isert_connect_request
> 
> On Mon, Mar 22, 2021 at 10:51:35PM +0800, lyl2019@mail.ustc.edu.cn wrote:
> > 
> > 
> > 
> > > -----原始邮件-----
> > > 发件人: "Leon Romanovsky" <leon@kernel.org>
> > > 发送时间: 2021-03-22 22:27:17 (星期一)
> > > 收件人: "Lv Yunlong" <lyl2019@mail.ustc.edu.cn>
> > > 抄送: sagi@grimberg.me, dledford@redhat.com, jgg@ziepe.ca, linux-rdma@vger.kernel.org, target-devel@vger.kernel.org, linux-kernel@vger.kernel.org
> > > 主题: Re: [PATCH] infiniband: Fix a use after free in isert_connect_request
> > > 
> > > On Mon, Mar 22, 2021 at 06:53:55AM -0700, Lv Yunlong wrote:
> > > > The device is got by isert_device_get() with refcount is 1,
> > > > and is assigned to isert_conn by isert_conn->device = device.
> > > > When isert_create_qp() failed, device will be freed with
> > > > isert_device_put().
> > > > 
> > > > Later, the device is used in isert_free_login_buf(isert_conn)
> > > > by the isert_conn->device->ib_device statement. My patch
> > > > exchanges the callees order to free the device late.
> > > > 
> > > > Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
> > > > ---
> > > >  drivers/infiniband/ulp/isert/ib_isert.c | 4 ++--
> > > >  1 file changed, 2 insertions(+), 2 deletions(-)
> > > 
> > > The fix needs to be change of isert_free_login_buf() from
> > > isert_free_login_buf(isert_conn) to be isert_free_login_buf(isert_conn, cma_id->device)
> > > 
> > > Thanks
> > > 
> > > > 
> > > > diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
> > > > index 7305ed8976c2..d8a533e346b0 100644
> > > > --- a/drivers/infiniband/ulp/isert/ib_isert.c
> > > > +++ b/drivers/infiniband/ulp/isert/ib_isert.c
> > > > @@ -473,10 +473,10 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
> > > >  
> > > >  out_destroy_qp:
> > > >  	isert_destroy_qp(isert_conn);
> > > > -out_conn_dev:
> > > > -	isert_device_put(device);
> > > >  out_rsp_dma_map:
> > > >  	isert_free_login_buf(isert_conn);
> > > > +out_conn_dev:
> > > > +	isert_device_put(device);
> > > >  out:
> > > >  	kfree(isert_conn);
> > > >  	rdma_reject(cma_id, NULL, 0, IB_CM_REJ_CONSUMER_DEFINED);
> > > > -- 
> > > > 2.25.1
> > > > 
> > > > 
> > 
> > I see that function isert_free_login_buf(struct isert_conn *isert_conn) has only
> > a parameter,  do you mean i need change the implementation of isert_free_login_buf?
> > 
> > I'm sorry to say that i am unfamilar with this module and afraid of making more mistakes,
> > because this function is being called elsewhere as well.
> > Could you help me to fix this issue? Or just fix it and tell me your commit number?
> 
> After checking how isert_connect_release() is implemented, it looks like
> this will fix:
> 
> diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
> index 7305ed8976c2..18266f07c58d 100644
> --- a/drivers/infiniband/ulp/isert/ib_isert.c
> +++ b/drivers/infiniband/ulp/isert/ib_isert.c
> @@ -438,23 +438,23 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
>  	isert_init_conn(isert_conn);
>  	isert_conn->cm_id = cma_id;
>  
> -	ret = isert_alloc_login_buf(isert_conn, cma_id->device);
> -	if (ret)
> -		goto out;
> -
>  	device = isert_device_get(cma_id);
>  	if (IS_ERR(device)) {
>  		ret = PTR_ERR(device);
> -		goto out_rsp_dma_map;
> +		goto out;
>  	}
>  	isert_conn->device = device;
>  
> +	ret = isert_alloc_login_buf(isert_conn, cma_id->device);
> +	if (ret)
> +		goto out_conn_dev;
> +
>  	isert_set_nego_params(isert_conn, &event->param.conn);
>  
>  	isert_conn->qp = isert_create_qp(isert_conn, cma_id);
>  	if (IS_ERR(isert_conn->qp)) {
>  		ret = PTR_ERR(isert_conn->qp);
> -		goto out_conn_dev;
> +		goto out_rsp_dma_map;
>  	}
>  
>  	ret = isert_login_post_recv(isert_conn);
> @@ -473,10 +473,10 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
>  
>  out_destroy_qp:
>  	isert_destroy_qp(isert_conn);
> -out_conn_dev:
> -	isert_device_put(device);
>  out_rsp_dma_map:
>  	isert_free_login_buf(isert_conn);
> +out_conn_dev:
> +	isert_device_put(device);
>  out:
>  	kfree(isert_conn);
>  	rdma_reject(cma_id, NULL, 0, IB_CM_REJ_CONSUMER_DEFINED);

Ok, i think this fixes this issue. 

I will commit a PATCH v2 later. Thank you very much.