* Re: [PATCH] RDMA/siw: Fix potential siw_mem refcnt leak in nr_add_node
2020-04-15 8:39 [PATCH] RDMA/siw: Fix potential siw_mem refcnt leak in nr_add_node Xiyu Yang
@ 2020-04-15 9:19 ` Bernard Metzler
2020-04-15 14:09 ` Jason Gunthorpe
2020-04-15 14:16 ` Bernard Metzler
2 siblings, 0 replies; 6+ messages in thread
From: Bernard Metzler @ 2020-04-15 9:19 UTC (permalink / raw)
To: Xiyu Yang
Cc: Doug Ledford, Jason Gunthorpe, linux-rdma, linux-kernel,
yuanxzhang, kjlu, Xin Tan
-----linux-rdma-owner@vger.kernel.org wrote: -----
>To: "Bernard Metzler" <bmt@zurich.ibm.com>, "Doug Ledford"
><dledford@redhat.com>, "Jason Gunthorpe" <jgg@ziepe.ca>,
>linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org
>From: "Xiyu Yang"
>Sent by: linux-rdma-owner@vger.kernel.org
>Date: 04/15/2020 10:46AM
>Cc: yuanxzhang@fudan.edu.cn, kjlu@umn.edu, "Xiyu Yang"
><xiyuyang19@fudan.edu.cn>, "Xin Tan" <tanxin.ctf@gmail.com>
>Subject: [EXTERNAL] [PATCH] RDMA/siw: Fix potential siw_mem refcnt
>leak in nr_add_node
>
>siw_fastreg_mr() invokes siw_mem_id2obj(), which returns a local
>reference of the siw_mem object to "mem" with increased refcnt.
>When siw_fastreg_mr() returns, "mem" becomes invalid, so the refcount
>should be decreased to keep refcount balanced.
>
>The issue happens in one error path of siw_fastreg_mr(). When
>"base_mr"
>equals to NULL but "mem" is not NULL, the function forgets to
>decrease
>the refcnt increased by siw_mem_id2obj() and causes a refcnt leak.
>
>Fix this issue by calling siw_mem_put() on this error path when mem
>is
>not NULL.
>
>Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
>Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
>---
> drivers/infiniband/sw/siw/siw_qp_tx.c | 2 ++
> 1 file changed, 2 insertions(+)
>
>diff --git a/drivers/infiniband/sw/siw/siw_qp_tx.c
>b/drivers/infiniband/sw/siw/siw_qp_tx.c
>index ae92c8080967..86044a44b83b 100644
>--- a/drivers/infiniband/sw/siw/siw_qp_tx.c
>+++ b/drivers/infiniband/sw/siw/siw_qp_tx.c
>@@ -926,6 +926,8 @@ static int siw_fastreg_mr(struct ib_pd *pd,
>struct siw_sqe *sqe)
> siw_dbg_pd(pd, "STag 0x%08x\n", sqe->rkey);
>
> if (unlikely(!mem || !base_mr)) {
>+ if (mem)
>+ siw_mem_put(mem);
> pr_warn("siw: fastreg: STag 0x%08x unknown\n", sqe->rkey);
> return -EINVAL;
> }
>--
I agree - thanks for the fix!
Reviewed-by: Bernard Metzler <bmt@zurich.ibm.com>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] RDMA/siw: Fix potential siw_mem refcnt leak in nr_add_node
2020-04-15 8:39 [PATCH] RDMA/siw: Fix potential siw_mem refcnt leak in nr_add_node Xiyu Yang
2020-04-15 9:19 ` Bernard Metzler
@ 2020-04-15 14:09 ` Jason Gunthorpe
2020-04-15 14:16 ` Bernard Metzler
2 siblings, 0 replies; 6+ messages in thread
From: Jason Gunthorpe @ 2020-04-15 14:09 UTC (permalink / raw)
To: Xiyu Yang
Cc: Bernard Metzler, Doug Ledford, linux-rdma, linux-kernel,
yuanxzhang, kjlu, Xin Tan
On Wed, Apr 15, 2020 at 04:39:08PM +0800, Xiyu Yang wrote:
> siw_fastreg_mr() invokes siw_mem_id2obj(), which returns a local
> reference of the siw_mem object to "mem" with increased refcnt.
> When siw_fastreg_mr() returns, "mem" becomes invalid, so the refcount
> should be decreased to keep refcount balanced.
>
> The issue happens in one error path of siw_fastreg_mr(). When "base_mr"
> equals to NULL but "mem" is not NULL, the function forgets to decrease
> the refcnt increased by siw_mem_id2obj() and causes a refcnt leak.
>
> Fix this issue by calling siw_mem_put() on this error path when mem is
> not NULL.
>
> Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
> drivers/infiniband/sw/siw/siw_qp_tx.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/infiniband/sw/siw/siw_qp_tx.c b/drivers/infiniband/sw/siw/siw_qp_tx.c
> index ae92c8080967..86044a44b83b 100644
> +++ b/drivers/infiniband/sw/siw/siw_qp_tx.c
> @@ -926,6 +926,8 @@ static int siw_fastreg_mr(struct ib_pd *pd, struct siw_sqe *sqe)
> siw_dbg_pd(pd, "STag 0x%08x\n", sqe->rkey);
>
> if (unlikely(!mem || !base_mr)) {
> + if (mem)
> + siw_mem_put(mem);
> pr_warn("siw: fastreg: STag 0x%08x unknown\n", sqe->rkey);
> return -EINVAL;
> }
I think I prefer this version, which is what I'll use if nobody has concerns:
diff --git a/drivers/infiniband/sw/siw/siw_qp_tx.c b/drivers/infiniband/sw/siw/siw_qp_tx.c
index ae92c8080967c5..0580bbf535ceb7 100644
--- a/drivers/infiniband/sw/siw/siw_qp_tx.c
+++ b/drivers/infiniband/sw/siw/siw_qp_tx.c
@@ -920,20 +920,28 @@ static int siw_fastreg_mr(struct ib_pd *pd, struct siw_sqe *sqe)
{
struct ib_mr *base_mr = (struct ib_mr *)(uintptr_t)sqe->base_mr;
struct siw_device *sdev = to_siw_dev(pd->device);
- struct siw_mem *mem = siw_mem_id2obj(sdev, sqe->rkey >> 8);
+ struct siw_mem *mem;
int rv = 0;
siw_dbg_pd(pd, "STag 0x%08x\n", sqe->rkey);
- if (unlikely(!mem || !base_mr)) {
+ if (unlikely(!base_mr)) {
pr_warn("siw: fastreg: STag 0x%08x unknown\n", sqe->rkey);
return -EINVAL;
}
+
if (unlikely(base_mr->rkey >> 8 != sqe->rkey >> 8)) {
pr_warn("siw: fastreg: STag 0x%08x: bad MR\n", sqe->rkey);
+ return -EINVAL;
+ }
+
+ mem = siw_mem_id2obj(sdev, sqe->rkey >> 8);
+ if (unlikely(!mem)) {
+ pr_warn("siw: fastreg: STag 0x%08x unknown\n", sqe->rkey);
rv = -EINVAL;
goto out;
}
+
if (unlikely(mem->pd != pd)) {
pr_warn("siw: fastreg: PD mismatch\n");
rv = -EINVAL;
^ permalink raw reply [flat|nested] 6+ messages in thread* RE: [PATCH] RDMA/siw: Fix potential siw_mem refcnt leak in nr_add_node
2020-04-15 8:39 [PATCH] RDMA/siw: Fix potential siw_mem refcnt leak in nr_add_node Xiyu Yang
2020-04-15 9:19 ` Bernard Metzler
2020-04-15 14:09 ` Jason Gunthorpe
@ 2020-04-15 14:16 ` Bernard Metzler
2020-04-15 14:27 ` Jason Gunthorpe
2 siblings, 1 reply; 6+ messages in thread
From: Bernard Metzler @ 2020-04-15 14:16 UTC (permalink / raw)
To: Jason Gunthorpe
Cc: Xiyu Yang, Doug Ledford, linux-rdma, linux-kernel, yuanxzhang,
kjlu, Xin Tan
-----"Jason Gunthorpe" <jgg@ziepe.ca> wrote: -----
>To: "Xiyu Yang" <xiyuyang19@fudan.edu.cn>
>From: "Jason Gunthorpe" <jgg@ziepe.ca>
>Date: 04/15/2020 04:09PM
>Cc: "Bernard Metzler" <bmt@zurich.ibm.com>, "Doug Ledford"
><dledford@redhat.com>, linux-rdma@vger.kernel.org,
>linux-kernel@vger.kernel.org, yuanxzhang@fudan.edu.cn, kjlu@umn.edu,
>"Xin Tan" <tanxin.ctf@gmail.com>
>Subject: [EXTERNAL] Re: [PATCH] RDMA/siw: Fix potential siw_mem
>refcnt leak in nr_add_node
>
>On Wed, Apr 15, 2020 at 04:39:08PM +0800, Xiyu Yang wrote:
>> siw_fastreg_mr() invokes siw_mem_id2obj(), which returns a local
>> reference of the siw_mem object to "mem" with increased refcnt.
>> When siw_fastreg_mr() returns, "mem" becomes invalid, so the
>refcount
>> should be decreased to keep refcount balanced.
>>
>> The issue happens in one error path of siw_fastreg_mr(). When
>"base_mr"
>> equals to NULL but "mem" is not NULL, the function forgets to
>decrease
>> the refcnt increased by siw_mem_id2obj() and causes a refcnt leak.
>>
>> Fix this issue by calling siw_mem_put() on this error path when mem
>is
>> not NULL.
>>
>> Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
>> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
>> drivers/infiniband/sw/siw/siw_qp_tx.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/infiniband/sw/siw/siw_qp_tx.c
>b/drivers/infiniband/sw/siw/siw_qp_tx.c
>> index ae92c8080967..86044a44b83b 100644
>> +++ b/drivers/infiniband/sw/siw/siw_qp_tx.c
>> @@ -926,6 +926,8 @@ static int siw_fastreg_mr(struct ib_pd *pd,
>struct siw_sqe *sqe)
>> siw_dbg_pd(pd, "STag 0x%08x\n", sqe->rkey);
>>
>> if (unlikely(!mem || !base_mr)) {
>> + if (mem)
>> + siw_mem_put(mem);
>> pr_warn("siw: fastreg: STag 0x%08x unknown\n", sqe->rkey);
>> return -EINVAL;
>> }
>
>I think I prefer this version, which is what I'll use if nobody has
>concerns:
>
>diff --git a/drivers/infiniband/sw/siw/siw_qp_tx.c
>b/drivers/infiniband/sw/siw/siw_qp_tx.c
>index ae92c8080967c5..0580bbf535ceb7 100644
>--- a/drivers/infiniband/sw/siw/siw_qp_tx.c
>+++ b/drivers/infiniband/sw/siw/siw_qp_tx.c
>@@ -920,20 +920,28 @@ static int siw_fastreg_mr(struct ib_pd *pd,
>struct siw_sqe *sqe)
> {
> struct ib_mr *base_mr = (struct ib_mr *)(uintptr_t)sqe->base_mr;
> struct siw_device *sdev = to_siw_dev(pd->device);
>- struct siw_mem *mem = siw_mem_id2obj(sdev, sqe->rkey >> 8);
>+ struct siw_mem *mem;
> int rv = 0;
>
> siw_dbg_pd(pd, "STag 0x%08x\n", sqe->rkey);
>
>- if (unlikely(!mem || !base_mr)) {
>+ if (unlikely(!base_mr)) {
> pr_warn("siw: fastreg: STag 0x%08x unknown\n", sqe->rkey);
> return -EINVAL;
> }
>+
> if (unlikely(base_mr->rkey >> 8 != sqe->rkey >> 8)) {
> pr_warn("siw: fastreg: STag 0x%08x: bad MR\n", sqe->rkey);
>+ return -EINVAL;
>+ }
>+
>+ mem = siw_mem_id2obj(sdev, sqe->rkey >> 8);
>+ if (unlikely(!mem)) {
>+ pr_warn("siw: fastreg: STag 0x%08x unknown\n", sqe->rkey);
> rv = -EINVAL;
> goto out;
> }
>+
Fine with me in principle, but we would have to return
directly here as well - since we do not have a valid mem
to be put back.
Thanks
Bernard.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] RDMA/siw: Fix potential siw_mem refcnt leak in nr_add_node
2020-04-15 14:16 ` Bernard Metzler
@ 2020-04-15 14:27 ` Jason Gunthorpe
0 siblings, 0 replies; 6+ messages in thread
From: Jason Gunthorpe @ 2020-04-15 14:27 UTC (permalink / raw)
To: Bernard Metzler
Cc: Xiyu Yang, Doug Ledford, linux-rdma, linux-kernel, yuanxzhang,
kjlu, Xin Tan
On Wed, Apr 15, 2020 at 02:16:54PM +0000, Bernard Metzler wrote:
> Fine with me in principle, but we would have to return
> directly here as well - since we do not have a valid mem
> to be put back.
Woops, yes, thanks
Jason
^ permalink raw reply [flat|nested] 6+ messages in thread