* [PATCH v2] RDMA/rxe: Prevent from double freeing rxe_map_set
@ 2021-12-28 1:44 Li Zhijian
2021-12-28 9:10 ` Zhu Yanjun
2022-01-05 0:44 ` Jason Gunthorpe
0 siblings, 2 replies; 3+ messages in thread
From: Li Zhijian @ 2021-12-28 1:44 UTC (permalink / raw)
To: zyjzyj2000, jgg
Cc: linux-rdma, linux-kernel, yanjun.zhu, rpearsonhpe, Li Zhijian,
Jason Gunthorpe
a same rxe_map_set could be freed twice:
rxe_reg_user_mr()
-> rxe_mr_init_user()
-> rxe_mr_free_map_set() # 1st
-> rxe_drop_ref()
...
-> rxe_mr_cleanup()
-> rxe_mr_free_map_set() # 2nd
By convention, we should cleanup/free resources in the error path in the
same function where the resources are alloted in. So rxe_mr_init_user()
doesn't need to free the map_set directly.
In addition, we have to reset map_set to NULL inside rxe_mr_alloc() if needed
to prevent from map_set being double freed in rxe_mr_cleanup().
CC: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
---
V2: Fix it by a simpler way by following suggestion from Bob,
---
drivers/infiniband/sw/rxe/rxe_mr.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c b/drivers/infiniband/sw/rxe/rxe_mr.c
index 25c78aade822..7c4cd19a9db2 100644
--- a/drivers/infiniband/sw/rxe/rxe_mr.c
+++ b/drivers/infiniband/sw/rxe/rxe_mr.c
@@ -141,6 +141,7 @@ static int rxe_mr_alloc(struct rxe_mr *mr, int num_buf, int both)
ret = rxe_mr_alloc_map_set(num_map, &mr->next_map_set);
if (ret) {
rxe_mr_free_map_set(mr->num_map, mr->cur_map_set);
+ mr->cur_map_set = NULL;
goto err_out;
}
}
@@ -214,7 +215,7 @@ int rxe_mr_init_user(struct rxe_pd *pd, u64 start, u64 length, u64 iova,
pr_warn("%s: Unable to get virtual address\n",
__func__);
err = -ENOMEM;
- goto err_cleanup_map;
+ goto err_release_umem;
}
buf->addr = (uintptr_t)vaddr;
@@ -237,8 +238,6 @@ int rxe_mr_init_user(struct rxe_pd *pd, u64 start, u64 length, u64 iova,
return 0;
-err_cleanup_map:
- rxe_mr_free_map_set(mr->num_map, mr->cur_map_set);
err_release_umem:
ib_umem_release(umem);
err_out:
--
2.31.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2] RDMA/rxe: Prevent from double freeing rxe_map_set
2021-12-28 1:44 [PATCH v2] RDMA/rxe: Prevent from double freeing rxe_map_set Li Zhijian
@ 2021-12-28 9:10 ` Zhu Yanjun
2022-01-05 0:44 ` Jason Gunthorpe
1 sibling, 0 replies; 3+ messages in thread
From: Zhu Yanjun @ 2021-12-28 9:10 UTC (permalink / raw)
To: Li Zhijian
Cc: Jason Gunthorpe, RDMA mailing list, LKML, yanjun.zhu,
Bob Pearson, Jason Gunthorpe
On Tue, Dec 28, 2021 at 9:39 AM Li Zhijian <lizhijian@cn.fujitsu.com> wrote:
>
> a same rxe_map_set could be freed twice:
> rxe_reg_user_mr()
> -> rxe_mr_init_user()
> -> rxe_mr_free_map_set() # 1st
> -> rxe_drop_ref()
> ...
> -> rxe_mr_cleanup()
> -> rxe_mr_free_map_set() # 2nd
>
> By convention, we should cleanup/free resources in the error path in the
> same function where the resources are alloted in. So rxe_mr_init_user()
> doesn't need to free the map_set directly.
>
> In addition, we have to reset map_set to NULL inside rxe_mr_alloc() if needed
> to prevent from map_set being double freed in rxe_mr_cleanup().
>
> CC: Jason Gunthorpe <jgg@nvidia.com>
> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Thanks.
Acked-by: Zhu Yanjun <zyjzyj2000@gmail.com>
Zhu Yanjun
> ---
> V2: Fix it by a simpler way by following suggestion from Bob,
> ---
> drivers/infiniband/sw/rxe/rxe_mr.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c b/drivers/infiniband/sw/rxe/rxe_mr.c
> index 25c78aade822..7c4cd19a9db2 100644
> --- a/drivers/infiniband/sw/rxe/rxe_mr.c
> +++ b/drivers/infiniband/sw/rxe/rxe_mr.c
> @@ -141,6 +141,7 @@ static int rxe_mr_alloc(struct rxe_mr *mr, int num_buf, int both)
> ret = rxe_mr_alloc_map_set(num_map, &mr->next_map_set);
> if (ret) {
> rxe_mr_free_map_set(mr->num_map, mr->cur_map_set);
> + mr->cur_map_set = NULL;
> goto err_out;
> }
> }
> @@ -214,7 +215,7 @@ int rxe_mr_init_user(struct rxe_pd *pd, u64 start, u64 length, u64 iova,
> pr_warn("%s: Unable to get virtual address\n",
> __func__);
> err = -ENOMEM;
> - goto err_cleanup_map;
> + goto err_release_umem;
> }
>
> buf->addr = (uintptr_t)vaddr;
> @@ -237,8 +238,6 @@ int rxe_mr_init_user(struct rxe_pd *pd, u64 start, u64 length, u64 iova,
>
> return 0;
>
> -err_cleanup_map:
> - rxe_mr_free_map_set(mr->num_map, mr->cur_map_set);
> err_release_umem:
> ib_umem_release(umem);
> err_out:
> --
> 2.31.1
>
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] RDMA/rxe: Prevent from double freeing rxe_map_set
2021-12-28 1:44 [PATCH v2] RDMA/rxe: Prevent from double freeing rxe_map_set Li Zhijian
2021-12-28 9:10 ` Zhu Yanjun
@ 2022-01-05 0:44 ` Jason Gunthorpe
1 sibling, 0 replies; 3+ messages in thread
From: Jason Gunthorpe @ 2022-01-05 0:44 UTC (permalink / raw)
To: Li Zhijian; +Cc: zyjzyj2000, linux-rdma, linux-kernel, yanjun.zhu, rpearsonhpe
On Tue, Dec 28, 2021 at 09:44:06AM +0800, Li Zhijian wrote:
> a same rxe_map_set could be freed twice:
> rxe_reg_user_mr()
> -> rxe_mr_init_user()
> -> rxe_mr_free_map_set() # 1st
> -> rxe_drop_ref()
> ...
> -> rxe_mr_cleanup()
> -> rxe_mr_free_map_set() # 2nd
>
> By convention, we should cleanup/free resources in the error path in the
> same function where the resources are alloted in. So rxe_mr_init_user()
> doesn't need to free the map_set directly.
>
> In addition, we have to reset map_set to NULL inside rxe_mr_alloc() if needed
> to prevent from map_set being double freed in rxe_mr_cleanup().
>
> CC: Jason Gunthorpe <jgg@nvidia.com>
> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
> Acked-by: Zhu Yanjun <zyjzyj2000@gmail.com>
> ---
> V2: Fix it by a simpler way by following suggestion from Bob,
> ---
> drivers/infiniband/sw/rxe/rxe_mr.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
Applied to for-rc, but I changed it to keep the goto unwind as is
normal.
@@ -135,19 +135,19 @@ static int rxe_mr_alloc(struct rxe_mr *mr, int num_buf, int both)
ret = rxe_mr_alloc_map_set(num_map, &mr->cur_map_set);
if (ret)
- goto err_out;
+ return -ENOMEM;
if (both) {
ret = rxe_mr_alloc_map_set(num_map, &mr->next_map_set);
- if (ret) {
- rxe_mr_free_map_set(mr->num_map, mr->cur_map_set);
- goto err_out;
- }
+ if (ret)
+ goto err_free;
}
return 0;
-err_out:
+err_free:
+ rxe_mr_free_map_set(mr->num_map, mr->cur_map_set);
+ mr->cur_map_set = NULL;
return -ENOMEM;
}
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-01-05 0:44 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2021-12-28 1:44 [PATCH v2] RDMA/rxe: Prevent from double freeing rxe_map_set Li Zhijian
2021-12-28 9:10 ` Zhu Yanjun
2022-01-05 0:44 ` Jason Gunthorpe
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