* Re: [PATCH net v2] net/smc: fix one NULL pointer dereference in smc_ib_is_sg_need_sync()
2025-08-28 12:41 [PATCH net v2] net/smc: fix one NULL pointer dereference in smc_ib_is_sg_need_sync() Liu Jian
@ 2025-08-28 13:04 ` Guangguan Wang
2025-08-28 18:24 ` yanjun.zhu
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Guangguan Wang @ 2025-08-28 13:04 UTC (permalink / raw)
To: Liu Jian, alibuda, dust.li, sidraya, wenjia, mjambigi, tonylu,
guwen, davem, edumazet, kuba, pabeni, horms
Cc: linux-rdma, linux-s390, netdev
在 2025/8/28 20:41, Liu Jian 写道:
> BUG: kernel NULL pointer dereference, address: 00000000000002ec
> PGD 0 P4D 0
> Oops: Oops: 0000 [#1] SMP PTI
> CPU: 28 UID: 0 PID: 343 Comm: kworker/28:1 Kdump: loaded Tainted: G OE 6.17.0-rc2+ #9 NONE
> Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
> Workqueue: smc_hs_wq smc_listen_work [smc]
> RIP: 0010:smc_ib_is_sg_need_sync+0x9e/0xd0 [smc]
> ...
> Call Trace:
> <TASK>
> smcr_buf_map_link+0x211/0x2a0 [smc]
> __smc_buf_create+0x522/0x970 [smc]
> smc_buf_create+0x3a/0x110 [smc]
> smc_find_rdma_v2_device_serv+0x18f/0x240 [smc]
> ? smc_vlan_by_tcpsk+0x7e/0xe0 [smc]
> smc_listen_find_device+0x1dd/0x2b0 [smc]
> smc_listen_work+0x30f/0x580 [smc]
> process_one_work+0x18c/0x340
> worker_thread+0x242/0x360
> kthread+0xe7/0x220
> ret_from_fork+0x13a/0x160
> ret_from_fork_asm+0x1a/0x30
> </TASK>
>
> If the software RoCE device is used, ibdev->dma_device is a null pointer.
> As a result, the problem occurs. Null pointer detection is added to
> prevent problems.
>
> Fixes: 0ef69e788411c ("net/smc: optimize for smc_sndbuf_sync_sg_for_device and smc_rmb_sync_sg_for_cpu")
> Signed-off-by: Liu Jian <liujian56@huawei.com>
> ---
> v1->v2:
> move the check outside of loop.
> net/smc/smc_ib.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c
> index 53828833a3f7..a42ef3f77b96 100644
> --- a/net/smc/smc_ib.c
> +++ b/net/smc/smc_ib.c
> @@ -742,6 +742,9 @@ bool smc_ib_is_sg_need_sync(struct smc_link *lnk,
> unsigned int i;
> bool ret = false;
>
> + if (!lnk->smcibdev->ibdev->dma_device)
> + return ret;
> +
> /* for now there is just one DMA address */
> for_each_sg(buf_slot->sgt[lnk->link_idx].sgl, sg,
> buf_slot->sgt[lnk->link_idx].nents, i) {
LGTM.
Reviewed-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH net v2] net/smc: fix one NULL pointer dereference in smc_ib_is_sg_need_sync()
2025-08-28 12:41 [PATCH net v2] net/smc: fix one NULL pointer dereference in smc_ib_is_sg_need_sync() Liu Jian
2025-08-28 13:04 ` Guangguan Wang
@ 2025-08-28 18:24 ` yanjun.zhu
2025-08-29 3:32 ` D. Wythe
2025-09-02 9:20 ` patchwork-bot+netdevbpf
3 siblings, 0 replies; 5+ messages in thread
From: yanjun.zhu @ 2025-08-28 18:24 UTC (permalink / raw)
To: Liu Jian, alibuda, dust.li, sidraya, wenjia, mjambigi, tonylu,
guwen, davem, edumazet, kuba, pabeni, horms, guangguan.wang
Cc: linux-rdma, linux-s390, netdev
On 8/28/25 5:41 AM, Liu Jian wrote:
> BUG: kernel NULL pointer dereference, address: 00000000000002ec
> PGD 0 P4D 0
> Oops: Oops: 0000 [#1] SMP PTI
> CPU: 28 UID: 0 PID: 343 Comm: kworker/28:1 Kdump: loaded Tainted: G OE 6.17.0-rc2+ #9 NONE
> Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
> Workqueue: smc_hs_wq smc_listen_work [smc]
> RIP: 0010:smc_ib_is_sg_need_sync+0x9e/0xd0 [smc]
> ...
> Call Trace:
> <TASK>
> smcr_buf_map_link+0x211/0x2a0 [smc]
> __smc_buf_create+0x522/0x970 [smc]
> smc_buf_create+0x3a/0x110 [smc]
> smc_find_rdma_v2_device_serv+0x18f/0x240 [smc]
> ? smc_vlan_by_tcpsk+0x7e/0xe0 [smc]
> smc_listen_find_device+0x1dd/0x2b0 [smc]
> smc_listen_work+0x30f/0x580 [smc]
> process_one_work+0x18c/0x340
> worker_thread+0x242/0x360
> kthread+0xe7/0x220
> ret_from_fork+0x13a/0x160
> ret_from_fork_asm+0x1a/0x30
> </TASK>
>
> If the software RoCE device is used, ibdev->dma_device is a null pointer.
> As a result, the problem occurs. Null pointer detection is added to
> prevent problems.
Normally, SoftRoCE relies on the DMA capabilities of the underlying NIC
device. In SMC, if DMA will play an important role in the subsequent
operations, we can leverage the NIC device’s DMA.
If DMA is not required for the upcoming actions, then this kind of
checking is sufficient.
Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Zhu Yanjun
>
> Fixes: 0ef69e788411c ("net/smc: optimize for smc_sndbuf_sync_sg_for_device and smc_rmb_sync_sg_for_cpu")
> Signed-off-by: Liu Jian <liujian56@huawei.com>
> ---
> v1->v2:
> move the check outside of loop.
> net/smc/smc_ib.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c
> index 53828833a3f7..a42ef3f77b96 100644
> --- a/net/smc/smc_ib.c
> +++ b/net/smc/smc_ib.c
> @@ -742,6 +742,9 @@ bool smc_ib_is_sg_need_sync(struct smc_link *lnk,
> unsigned int i;
> bool ret = false;
>
> + if (!lnk->smcibdev->ibdev->dma_device)
> + return ret;
> +
> /* for now there is just one DMA address */
> for_each_sg(buf_slot->sgt[lnk->link_idx].sgl, sg,
> buf_slot->sgt[lnk->link_idx].nents, i) {
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH net v2] net/smc: fix one NULL pointer dereference in smc_ib_is_sg_need_sync()
2025-08-28 12:41 [PATCH net v2] net/smc: fix one NULL pointer dereference in smc_ib_is_sg_need_sync() Liu Jian
2025-08-28 13:04 ` Guangguan Wang
2025-08-28 18:24 ` yanjun.zhu
@ 2025-08-29 3:32 ` D. Wythe
2025-09-02 9:20 ` patchwork-bot+netdevbpf
3 siblings, 0 replies; 5+ messages in thread
From: D. Wythe @ 2025-08-29 3:32 UTC (permalink / raw)
To: Liu Jian
Cc: alibuda, dust.li, sidraya, wenjia, mjambigi, tonylu, guwen, davem,
edumazet, kuba, pabeni, horms, guangguan.wang, linux-rdma,
linux-s390, netdev
On Thu, Aug 28, 2025 at 08:41:17PM +0800, Liu Jian wrote:
> BUG: kernel NULL pointer dereference, address: 00000000000002ec
> PGD 0 P4D 0
> Oops: Oops: 0000 [#1] SMP PTI
> CPU: 28 UID: 0 PID: 343 Comm: kworker/28:1 Kdump: loaded Tainted: G OE 6.17.0-rc2+ #9 NONE
> Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
> Workqueue: smc_hs_wq smc_listen_work [smc]
> RIP: 0010:smc_ib_is_sg_need_sync+0x9e/0xd0 [smc]
> ...
> Call Trace:
> <TASK>
> smcr_buf_map_link+0x211/0x2a0 [smc]
> __smc_buf_create+0x522/0x970 [smc]
> smc_buf_create+0x3a/0x110 [smc]
> smc_find_rdma_v2_device_serv+0x18f/0x240 [smc]
> ? smc_vlan_by_tcpsk+0x7e/0xe0 [smc]
> smc_listen_find_device+0x1dd/0x2b0 [smc]
> smc_listen_work+0x30f/0x580 [smc]
> process_one_work+0x18c/0x340
> worker_thread+0x242/0x360
> kthread+0xe7/0x220
> ret_from_fork+0x13a/0x160
> ret_from_fork_asm+0x1a/0x30
> </TASK>
>
> If the software RoCE device is used, ibdev->dma_device is a null pointer.
> As a result, the problem occurs. Null pointer detection is added to
> prevent problems.
>
> Fixes: 0ef69e788411c ("net/smc: optimize for smc_sndbuf_sync_sg_for_device and smc_rmb_sync_sg_for_cpu")
> Signed-off-by: Liu Jian <liujian56@huawei.com>
> ---
> v1->v2:
> move the check outside of loop.
> net/smc/smc_ib.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c
> index 53828833a3f7..a42ef3f77b96 100644
> --- a/net/smc/smc_ib.c
> +++ b/net/smc/smc_ib.c
> @@ -742,6 +742,9 @@ bool smc_ib_is_sg_need_sync(struct smc_link *lnk,
> unsigned int i;
> bool ret = false;
>
> + if (!lnk->smcibdev->ibdev->dma_device)
> + return ret;
> +
> /* for now there is just one DMA address */
> for_each_sg(buf_slot->sgt[lnk->link_idx].sgl, sg,
> buf_slot->sgt[lnk->link_idx].nents, i) {
LGTM, thanks.
Reviewed-by: D. Wythe <alibuda@linux.alibaba.com>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH net v2] net/smc: fix one NULL pointer dereference in smc_ib_is_sg_need_sync()
2025-08-28 12:41 [PATCH net v2] net/smc: fix one NULL pointer dereference in smc_ib_is_sg_need_sync() Liu Jian
` (2 preceding siblings ...)
2025-08-29 3:32 ` D. Wythe
@ 2025-09-02 9:20 ` patchwork-bot+netdevbpf
3 siblings, 0 replies; 5+ messages in thread
From: patchwork-bot+netdevbpf @ 2025-09-02 9:20 UTC (permalink / raw)
To: Liu Jian
Cc: alibuda, dust.li, sidraya, wenjia, mjambigi, tonylu, guwen, davem,
edumazet, kuba, pabeni, horms, guangguan.wang, linux-rdma,
linux-s390, netdev
Hello:
This patch was applied to netdev/net.git (main)
by Paolo Abeni <pabeni@redhat.com>:
On Thu, 28 Aug 2025 20:41:17 +0800 you wrote:
> BUG: kernel NULL pointer dereference, address: 00000000000002ec
> PGD 0 P4D 0
> Oops: Oops: 0000 [#1] SMP PTI
> CPU: 28 UID: 0 PID: 343 Comm: kworker/28:1 Kdump: loaded Tainted: G OE 6.17.0-rc2+ #9 NONE
> Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
> Workqueue: smc_hs_wq smc_listen_work [smc]
> RIP: 0010:smc_ib_is_sg_need_sync+0x9e/0xd0 [smc]
> ...
> Call Trace:
> <TASK>
> smcr_buf_map_link+0x211/0x2a0 [smc]
> __smc_buf_create+0x522/0x970 [smc]
> smc_buf_create+0x3a/0x110 [smc]
> smc_find_rdma_v2_device_serv+0x18f/0x240 [smc]
> ? smc_vlan_by_tcpsk+0x7e/0xe0 [smc]
> smc_listen_find_device+0x1dd/0x2b0 [smc]
> smc_listen_work+0x30f/0x580 [smc]
> process_one_work+0x18c/0x340
> worker_thread+0x242/0x360
> kthread+0xe7/0x220
> ret_from_fork+0x13a/0x160
> ret_from_fork_asm+0x1a/0x30
> </TASK>
>
> [...]
Here is the summary with links:
- [net,v2] net/smc: fix one NULL pointer dereference in smc_ib_is_sg_need_sync()
https://git.kernel.org/netdev/net/c/ba1e9421cf1a
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 5+ messages in thread