[v1] RDMA/uverbs: fix umem release in UVERBS_METHOD_CQ_CREATE

[PATCH] RDMA/uverbs: fix umem release in UVERBS_METHOD_CQ_CREATE

Posted by Shuhao Fu 2 months, 1 week ago

In `UVERBS_METHOD_CQ_CREATE`, umem should be released if anything goes
wrong. Currently, if `create_cq_umem` fails, umem would not be
released or referenced, causing a possible leak.

Fixes: 1a40c362ae26 ("RDMA/uverbs: Add a common way to create CQ with umem")
Signed-off-by: Shuhao Fu <sfual@cse.ust.hk>
---
 drivers/infiniband/core/uverbs_std_types_cq.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/uverbs_std_types_cq.c b/drivers/infiniband/core/uverbs_std_types_cq.c
index 37cd37556510..9344020dede1 100644
--- a/drivers/infiniband/core/uverbs_std_types_cq.c
+++ b/drivers/infiniband/core/uverbs_std_types_cq.c
@@ -193,8 +193,10 @@ static int UVERBS_HANDLER(UVERBS_METHOD_CQ_CREATE)(
 
 	ret = umem ? ib_dev->ops.create_cq_umem(cq, &attr, umem, attrs) :
 		ib_dev->ops.create_cq(cq, &attr, attrs);
-	if (ret)
+	if (ret) {
+		ib_umem_release(umem);
 		goto err_free;
+	}
 
 	obj->uevent.uobject.object = cq;
 	obj->uevent.uobject.user_handle = user_handle;
-- 
2.39.5

Re: [PATCH] RDMA/uverbs: fix umem release in UVERBS_METHOD_CQ_CREATE

Posted by Leon Romanovsky 2 months, 1 week ago

On Fri, Oct 10, 2025 at 12:40:26AM +0800, Shuhao Fu wrote:
> In `UVERBS_METHOD_CQ_CREATE`, umem should be released if anything goes
> wrong. Currently, if `create_cq_umem` fails, umem would not be
> released or referenced, causing a possible leak.

It is only partially true. UMEM is released inside .create_cq_umem()
implementation. However there is an issue there that it doesn't release
in all flows. You need to change efa_create_cq_umem() too.

> 
> Fixes: 1a40c362ae26 ("RDMA/uverbs: Add a common way to create CQ with umem")
> Signed-off-by: Shuhao Fu <sfual@cse.ust.hk>
> ---
>  drivers/infiniband/core/uverbs_std_types_cq.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/infiniband/core/uverbs_std_types_cq.c b/drivers/infiniband/core/uverbs_std_types_cq.c
> index 37cd37556510..9344020dede1 100644
> --- a/drivers/infiniband/core/uverbs_std_types_cq.c
> +++ b/drivers/infiniband/core/uverbs_std_types_cq.c
> @@ -193,8 +193,10 @@ static int UVERBS_HANDLER(UVERBS_METHOD_CQ_CREATE)(
>  
>  	ret = umem ? ib_dev->ops.create_cq_umem(cq, &attr, umem, attrs) :
>  		ib_dev->ops.create_cq(cq, &attr, attrs);
> -	if (ret)
> +	if (ret) {
> +		ib_umem_release(umem);
>  		goto err_free;
> +	}
>  
>  	obj->uevent.uobject.object = cq;
>  	obj->uevent.uobject.user_handle = user_handle;
> -- 
> 2.39.5
> 
>

Re: [PATCH] RDMA/uverbs: fix umem release in UVERBS_METHOD_CQ_CREATE

Posted by Shuhao Fu 2 months, 1 week ago

On Thu, Oct 09, 2025 at 09:48:54PM +0300, Leon Romanovsky wrote:
> On Fri, Oct 10, 2025 at 12:40:26AM +0800, Shuhao Fu wrote:
> > In `UVERBS_METHOD_CQ_CREATE`, umem should be released if anything goes
> > wrong. Currently, if `create_cq_umem` fails, umem would not be
> > released or referenced, causing a possible leak.
> 
> It is only partially true. UMEM is released inside .create_cq_umem()
> implementation. However there is an issue there that it doesn't release
> in all flows. You need to change efa_create_cq_umem() too.
> 

My apologies for overlooking the umem release in `.create_cq_umem`. I have
sent out patch v2 [1] for this issue. In v2, the driver should not release
umem on failure, avoiding possible double free here.

[1] https://lore.kernel.org/linux-rdma/aOh1le4YqtYwj-hH@osx.local/

> > 
> > Fixes: 1a40c362ae26 ("RDMA/uverbs: Add a common way to create CQ with umem")
> > Signed-off-by: Shuhao Fu <sfual@cse.ust.hk>
> > ---
> >  drivers/infiniband/core/uverbs_std_types_cq.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/infiniband/core/uverbs_std_types_cq.c b/drivers/infiniband/core/uverbs_std_types_cq.c
> > index 37cd37556510..9344020dede1 100644
> > --- a/drivers/infiniband/core/uverbs_std_types_cq.c
> > +++ b/drivers/infiniband/core/uverbs_std_types_cq.c
> > @@ -193,8 +193,10 @@ static int UVERBS_HANDLER(UVERBS_METHOD_CQ_CREATE)(
> >  
> >  	ret = umem ? ib_dev->ops.create_cq_umem(cq, &attr, umem, attrs) :
> >  		ib_dev->ops.create_cq(cq, &attr, attrs);
> > -	if (ret)
> > +	if (ret) {
> > +		ib_umem_release(umem);
> >  		goto err_free;
> > +	}
> >  
> >  	obj->uevent.uobject.object = cq;
> >  	obj->uevent.uobject.user_handle = user_handle;
> > -- 
> > 2.39.5
> > 
> >