[PATCH] RDMA/rxe: Fix null pointer dereference in ODP MR check

[PATCH] RDMA/rxe: Fix null pointer dereference in ODP MR check

[Li Zhijian]

The blktests/rnbd reported a null pointer dereference as following.
Similar to the mxl5, introduce a is_odp_mr() to check if the odp
is enabled in this mr.

Workqueue: rxe_wq do_work [rdma_rxe]
RIP: 0010:rxe_mr_copy+0x57/0x210 [rdma_rxe]
Code: 7c 04 48 89 f3 48 89 d5 41 89 cf 45 89 c4 0f 84 dc 00 00 00 89 ca e8 f8 f8 ff ff 85 c0 0f 85 75 01 00 00 49 8b 86 f0 00 00 00 <f6> 40 28 02 0f 85 98 01 00 00 41 8b 46 78 41 8b 8e 10 01 00 00 8d
RSP: 0018:ffffa0aac02cfcf8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff9079cd440024 RCX: 0000000000000000
RDX: 000000000000003c RSI: ffff9079cd440060 RDI: ffff9079cd665600
RBP: ffff9079c0e5e45a R08: 0000000000000000 R09: 0000000000000000
R10: 000000003c000000 R11: 0000000000225510 R12: 0000000000000000
R13: 0000000000000000 R14: ffff9079cd665600 R15: 000000000000003c
FS:  0000000000000000(0000) GS:ffff907ccfa80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000028 CR3: 0000000119498001 CR4: 00000000001726f0
Call Trace:
 <TASK>
 ? __die_body+0x1e/0x60
 ? page_fault_oops+0x14f/0x4c0
 ? rxe_mr_copy+0x57/0x210 [rdma_rxe]
 ? search_bpf_extables+0x5f/0x80
 ? exc_page_fault+0x7e/0x180
 ? asm_exc_page_fault+0x26/0x30
 ? rxe_mr_copy+0x57/0x210 [rdma_rxe]
 ? rxe_mr_copy+0x48/0x210 [rdma_rxe]
 ? rxe_pool_get_index+0x50/0x90 [rdma_rxe]
 rxe_receiver+0x1d98/0x2530 [rdma_rxe]
 ? psi_task_switch+0x1ff/0x250
 ? finish_task_switch+0x92/0x2d0
 ? __schedule+0xbdf/0x17c0
 do_task+0x65/0x1e0 [rdma_rxe]
 process_scheduled_works+0xaa/0x3f0
 worker_thread+0x117/0x240

Fixes: d03fb5c6599e ("RDMA/rxe: Allow registering MRs for On-Demand Paging")
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
---
 drivers/infiniband/sw/rxe/rxe_loc.h  | 6 ++++++
 drivers/infiniband/sw/rxe/rxe_mr.c   | 4 ++--
 drivers/infiniband/sw/rxe/rxe_resp.c | 4 ++--
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_loc.h b/drivers/infiniband/sw/rxe/rxe_loc.h
index feb386d98d1d..0bc3fbb6554f 100644
--- a/drivers/infiniband/sw/rxe/rxe_loc.h
+++ b/drivers/infiniband/sw/rxe/rxe_loc.h
@@ -140,6 +140,12 @@ static inline int qp_mtu(struct rxe_qp *qp)
 		return IB_MTU_4096;
 }
 
+static inline bool is_odp_mr(struct rxe_mr *mr)
+{
+	return IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING) && mr->umem &&
+	       mr->umem->is_odp;
+}
+
 void free_rd_atomic_resource(struct resp_res *res);
 
 static inline void rxe_advance_resp_resource(struct rxe_qp *qp)
diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c b/drivers/infiniband/sw/rxe/rxe_mr.c
index 868d2f0b74e9..432d864c3ce9 100644
--- a/drivers/infiniband/sw/rxe/rxe_mr.c
+++ b/drivers/infiniband/sw/rxe/rxe_mr.c
@@ -323,7 +323,7 @@ int rxe_mr_copy(struct rxe_mr *mr, u64 iova, void *addr,
 		return err;
 	}
 
-	if (mr->umem->is_odp)
+	if (is_odp_mr(mr))
 		return rxe_odp_mr_copy(mr, iova, addr, length, dir);
 	else
 		return rxe_mr_copy_xarray(mr, iova, addr, length, dir);
@@ -536,7 +536,7 @@ int rxe_mr_do_atomic_write(struct rxe_mr *mr, u64 iova, u64 value)
 	u64 *va;
 
 	/* ODP is not supported right now. WIP. */
-	if (mr->umem->is_odp)
+	if (is_odp_mr(mr))
 		return RESPST_ERR_UNSUPPORTED_OPCODE;
 
 	/* See IBA oA19-28 */
diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
index 54ba9ee1acc5..5d9174e408db 100644
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -650,7 +650,7 @@ static enum resp_states process_flush(struct rxe_qp *qp,
 	struct resp_res *res = qp->resp.res;
 
 	/* ODP is not supported right now. WIP. */
-	if (mr->umem->is_odp)
+	if (is_odp_mr(mr))
 		return RESPST_ERR_UNSUPPORTED_OPCODE;
 
 	/* oA19-14, oA19-15 */
@@ -706,7 +706,7 @@ static enum resp_states atomic_reply(struct rxe_qp *qp,
 	if (!res->replay) {
 		u64 iova = qp->resp.va + qp->resp.offset;
 
-		if (mr->umem->is_odp)
+		if (is_odp_mr(mr))
 			err = rxe_odp_atomic_op(mr, iova, pkt->opcode,
 						atmeth_comp(pkt),
 						atmeth_swap_add(pkt),
-- 
2.41.0

RE: [PATCH] RDMA/rxe: Fix null pointer dereference in ODP MR check

[Daisuke Matsuda (Fujitsu)]

On Wed, April 2, 2025 12:27 PM Li Zhijian wrote:
> 
> The blktests/rnbd reported a null pointer dereference as following.
> Similar to the mxl5, introduce a is_odp_mr() to check if the odp

Typo: mxl5
Can this be amended when merging?

> is enabled in this mr.
> 

Thank you for the fix!
If mr type is other than IB_MR_TYPE_USER, the null pointer dereference can occur
since mr->umem is not set in that case. The fix looks good.

Reviewed-by: Daisuke Matsuda <matsuda-daisuke@fujitsu.com>

Re: [PATCH] RDMA/rxe: Fix null pointer dereference in ODP MR check

[Zhu Yanjun]

在 2025/4/2 5:26, Li Zhijian 写道:
> The blktests/rnbd reported a null pointer dereference as following.
> Similar to the mxl5, introduce a is_odp_mr() to check if the odp
> is enabled in this mr.
> 
> Workqueue: rxe_wq do_work [rdma_rxe]
> RIP: 0010:rxe_mr_copy+0x57/0x210 [rdma_rxe]
> Code: 7c 04 48 89 f3 48 89 d5 41 89 cf 45 89 c4 0f 84 dc 00 00 00 89 ca e8 f8 f8 ff ff 85 c0 0f 85 75 01 00 00 49 8b 86 f0 00 00 00 <f6> 40 28 02 0f 85 98 01 00 00 41 8b 46 78 41 8b 8e 10 01 00 00 8d
> RSP: 0018:ffffa0aac02cfcf8 EFLAGS: 00010246
> RAX: 0000000000000000 RBX: ffff9079cd440024 RCX: 0000000000000000
> RDX: 000000000000003c RSI: ffff9079cd440060 RDI: ffff9079cd665600
> RBP: ffff9079c0e5e45a R08: 0000000000000000 R09: 0000000000000000
> R10: 000000003c000000 R11: 0000000000225510 R12: 0000000000000000
> R13: 0000000000000000 R14: ffff9079cd665600 R15: 000000000000003c
> FS:  0000000000000000(0000) GS:ffff907ccfa80000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000028 CR3: 0000000119498001 CR4: 00000000001726f0
> Call Trace:
>   <TASK>
>   ? __die_body+0x1e/0x60
>   ? page_fault_oops+0x14f/0x4c0
>   ? rxe_mr_copy+0x57/0x210 [rdma_rxe]
>   ? search_bpf_extables+0x5f/0x80
>   ? exc_page_fault+0x7e/0x180
>   ? asm_exc_page_fault+0x26/0x30
>   ? rxe_mr_copy+0x57/0x210 [rdma_rxe]
>   ? rxe_mr_copy+0x48/0x210 [rdma_rxe]
>   ? rxe_pool_get_index+0x50/0x90 [rdma_rxe]
>   rxe_receiver+0x1d98/0x2530 [rdma_rxe]
>   ? psi_task_switch+0x1ff/0x250
>   ? finish_task_switch+0x92/0x2d0
>   ? __schedule+0xbdf/0x17c0
>   do_task+0x65/0x1e0 [rdma_rxe]
>   process_scheduled_works+0xaa/0x3f0
>   worker_thread+0x117/0x240
> 
> Fixes: d03fb5c6599e ("RDMA/rxe: Allow registering MRs for On-Demand Paging")
> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
> ---
>   drivers/infiniband/sw/rxe/rxe_loc.h  | 6 ++++++
>   drivers/infiniband/sw/rxe/rxe_mr.c   | 4 ++--
>   drivers/infiniband/sw/rxe/rxe_resp.c | 4 ++--
>   3 files changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/infiniband/sw/rxe/rxe_loc.h b/drivers/infiniband/sw/rxe/rxe_loc.h
> index feb386d98d1d..0bc3fbb6554f 100644
> --- a/drivers/infiniband/sw/rxe/rxe_loc.h
> +++ b/drivers/infiniband/sw/rxe/rxe_loc.h
> @@ -140,6 +140,12 @@ static inline int qp_mtu(struct rxe_qp *qp)
>   		return IB_MTU_4096;
>   }
>   
> +static inline bool is_odp_mr(struct rxe_mr *mr)

Previously I once discussed with Bob Pearson about the function names.
Perhaps it is better to rename is_odp_mr to rxe_is_odp_mr?

Since sometimes we debug in rdma, with a lot of functions with the same 
name, it is difficult to recognize the modules that this function 
belongs to.

Thus, in rxe module, it is better to add rxe_ prefix to the function 
name. But anyway, this commit is fine.

Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>

Zhu Yanjun

> +{
> +	return IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING) && mr->umem &&
> +	       mr->umem->is_odp;
> +}
> +
>   void free_rd_atomic_resource(struct resp_res *res);
>   
>   static inline void rxe_advance_resp_resource(struct rxe_qp *qp)
> diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c b/drivers/infiniband/sw/rxe/rxe_mr.c
> index 868d2f0b74e9..432d864c3ce9 100644
> --- a/drivers/infiniband/sw/rxe/rxe_mr.c
> +++ b/drivers/infiniband/sw/rxe/rxe_mr.c
> @@ -323,7 +323,7 @@ int rxe_mr_copy(struct rxe_mr *mr, u64 iova, void *addr,
>   		return err;
>   	}
>   
> -	if (mr->umem->is_odp)
> +	if (is_odp_mr(mr))
>   		return rxe_odp_mr_copy(mr, iova, addr, length, dir);
>   	else
>   		return rxe_mr_copy_xarray(mr, iova, addr, length, dir);
> @@ -536,7 +536,7 @@ int rxe_mr_do_atomic_write(struct rxe_mr *mr, u64 iova, u64 value)
>   	u64 *va;
>   
>   	/* ODP is not supported right now. WIP. */
> -	if (mr->umem->is_odp)
> +	if (is_odp_mr(mr))
>   		return RESPST_ERR_UNSUPPORTED_OPCODE;
>   
>   	/* See IBA oA19-28 */
> diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
> index 54ba9ee1acc5..5d9174e408db 100644
> --- a/drivers/infiniband/sw/rxe/rxe_resp.c
> +++ b/drivers/infiniband/sw/rxe/rxe_resp.c
> @@ -650,7 +650,7 @@ static enum resp_states process_flush(struct rxe_qp *qp,
>   	struct resp_res *res = qp->resp.res;
>   
>   	/* ODP is not supported right now. WIP. */
> -	if (mr->umem->is_odp)
> +	if (is_odp_mr(mr))
>   		return RESPST_ERR_UNSUPPORTED_OPCODE;
>   
>   	/* oA19-14, oA19-15 */
> @@ -706,7 +706,7 @@ static enum resp_states atomic_reply(struct rxe_qp *qp,
>   	if (!res->replay) {
>   		u64 iova = qp->resp.va + qp->resp.offset;
>   
> -		if (mr->umem->is_odp)
> +		if (is_odp_mr(mr))
>   			err = rxe_odp_atomic_op(mr, iova, pkt->opcode,
>   						atmeth_comp(pkt),
>   						atmeth_swap_add(pkt),

Re: [PATCH] RDMA/rxe: Fix null pointer dereference in ODP MR check

[Zhijian Li (Fujitsu)]

On 02/04/2025 16:58, Zhu Yanjun wrote:
> 
> Previously I once discussed with Bob Pearson about the function names.

This is a frequently raised question, yet I have not discovered a definitive
coding style(Please let me know if you have). According to my understanding,
the common practice I adhere to is as follows:

- Functions utilized within a single file often do not require a prefix, as current situation.
- If a function is to be used across multiple files, I believe a prefix is essential.

Thanks
Zhijian

> Perhaps it is better to rename is_odp_mr to rxe_is_odp_mr?
> 
> Since sometimes we debug in rdma, with a lot of functions with the same name, it is difficult to recognize the modules that this function belongs to.
> 
> Thus, in rxe module, it is better to add rxe_ prefix to the function name. But anyway, this commit is fine.

Re: [PATCH] RDMA/rxe: Fix null pointer dereference in ODP MR check

[Zhu Yanjun]

在 2025/4/3 4:59, Zhijian Li (Fujitsu) 写道:
> 
> 
> On 02/04/2025 16:58, Zhu Yanjun wrote:
>>
>> Previously I once discussed with Bob Pearson about the function names.
> 
> This is a frequently raised question, yet I have not discovered a definitive
> coding style(Please let me know if you have). According to my understanding,
> the common practice I adhere to is as follows:
> 

You have your own principals. In the linux rdma maillist, there is no 
such common principals. From the debug perspective, it is better to add 
rxe_ prefix to make debuf life easier. But if you follow your advice to 
choose not to add rxe_ prefix, it is also OK. After all, no such 
principals exist currently.

Zhu Yanjun

> - Functions utilized within a single file often do not require a prefix, as current situation.
> - If a function is to be used across multiple files, I believe a prefix is essential.
> 
> Thanks
> Zhijian
> 
>> Perhaps it is better to rename is_odp_mr to rxe_is_odp_mr?
>>
>> Since sometimes we debug in rdma, with a lot of functions with the same name, it is difficult to recognize the modules that this function belongs to.
>>
>> Thus, in rxe module, it is better to add rxe_ prefix to the function name. But anyway, this commit is fine.

Re: [PATCH] RDMA/rxe: Fix null pointer dereference in ODP MR check

[Jason Gunthorpe]

On Wed, Apr 02, 2025 at 11:26:57AM +0800, Li Zhijian wrote:
> The blktests/rnbd reported a null pointer dereference as following.
> Similar to the mxl5, introduce a is_odp_mr() to check if the odp
> is enabled in this mr.
> 
> Workqueue: rxe_wq do_work [rdma_rxe]
> RIP: 0010:rxe_mr_copy+0x57/0x210 [rdma_rxe]
> Code: 7c 04 48 89 f3 48 89 d5 41 89 cf 45 89 c4 0f 84 dc 00 00 00 89 ca e8 f8 f8 ff ff 85 c0 0f 85 75 01 00 00 49 8b 86 f0 00 00 00 <f6> 40 28 02 0f 85 98 01 00 00 41 8b 46 78 41 8b 8e 10 01 00 00 8d
> RSP: 0018:ffffa0aac02cfcf8 EFLAGS: 00010246
> RAX: 0000000000000000 RBX: ffff9079cd440024 RCX: 0000000000000000
> RDX: 000000000000003c RSI: ffff9079cd440060 RDI: ffff9079cd665600
> RBP: ffff9079c0e5e45a R08: 0000000000000000 R09: 0000000000000000
> R10: 000000003c000000 R11: 0000000000225510 R12: 0000000000000000
> R13: 0000000000000000 R14: ffff9079cd665600 R15: 000000000000003c
> FS:  0000000000000000(0000) GS:ffff907ccfa80000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000028 CR3: 0000000119498001 CR4: 00000000001726f0
> Call Trace:
>  <TASK>
>  ? __die_body+0x1e/0x60
>  ? page_fault_oops+0x14f/0x4c0
>  ? rxe_mr_copy+0x57/0x210 [rdma_rxe]
>  ? search_bpf_extables+0x5f/0x80
>  ? exc_page_fault+0x7e/0x180
>  ? asm_exc_page_fault+0x26/0x30
>  ? rxe_mr_copy+0x57/0x210 [rdma_rxe]
>  ? rxe_mr_copy+0x48/0x210 [rdma_rxe]
>  ? rxe_pool_get_index+0x50/0x90 [rdma_rxe]
>  rxe_receiver+0x1d98/0x2530 [rdma_rxe]
>  ? psi_task_switch+0x1ff/0x250
>  ? finish_task_switch+0x92/0x2d0
>  ? __schedule+0xbdf/0x17c0
>  do_task+0x65/0x1e0 [rdma_rxe]
>  process_scheduled_works+0xaa/0x3f0
>  worker_thread+0x117/0x240
> 
> Fixes: d03fb5c6599e ("RDMA/rxe: Allow registering MRs for On-Demand Paging")
> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
> Reviewed-by: Daisuke Matsuda <matsuda-daisuke@fujitsu.com>
> Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
> ---
>  drivers/infiniband/sw/rxe/rxe_loc.h  | 6 ++++++
>  drivers/infiniband/sw/rxe/rxe_mr.c   | 4 ++--
>  drivers/infiniband/sw/rxe/rxe_resp.c | 4 ++--
>  3 files changed, 10 insertions(+), 4 deletions(-)

Applied to for-rc, thanks

Jason