2022-11-01 10:45:10

by Chen Zhongjin

[permalink] [raw]
Subject: [PATCH] net/smc: Fix possible leaked pernet namespace in smc_init()

In smc_init(), register_pernet_subsys(&smc_net_stat_ops) is called
without any error handling.
If it fails, registering of &smc_net_ops won't be reverted.
And if smc_nl_init() fails, &smc_net_stat_ops itself won't be reverted.

This leaves wild ops in subsystem linkedlist and when another module
tries to call register_pernet_operations() it triggers page fault:

BUG: unable to handle page fault for address: fffffbfff81b964c
RIP: 0010:register_pernet_operations+0x1b9/0x5f0
Call Trace:
<TASK>
register_pernet_subsys+0x29/0x40
ebtables_init+0x58/0x1000 [ebtables]
...

Fixes: 194730a9beb5 ("net/smc: Make SMC statistics network namespace aware")
Signed-off-by: Chen Zhongjin <[email protected]>
---
net/smc/af_smc.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 3ccbf3c201cd..e12d4fa5aece 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -3380,14 +3380,14 @@ static int __init smc_init(void)

rc = register_pernet_subsys(&smc_net_stat_ops);
if (rc)
- return rc;
+ goto out_pernet_subsys;

smc_ism_init();
smc_clc_init();

rc = smc_nl_init();
if (rc)
- goto out_pernet_subsys;
+ goto out_pernet_subsys_stat;

rc = smc_pnet_init();
if (rc)
@@ -3480,6 +3480,8 @@ static int __init smc_init(void)
smc_pnet_exit();
out_nl:
smc_nl_exit();
+out_pernet_subsys_stat:
+ unregister_pernet_subsys(&smc_net_stat_ops);
out_pernet_subsys:
unregister_pernet_subsys(&smc_net_ops);

--
2.17.1



2022-11-01 11:17:40

by Tony Lu

[permalink] [raw]
Subject: Re: [PATCH] net/smc: Fix possible leaked pernet namespace in smc_init()

On Tue, Nov 01, 2022 at 05:37:22PM +0800, Chen Zhongjin wrote:
> In smc_init(), register_pernet_subsys(&smc_net_stat_ops) is called
> without any error handling.
> If it fails, registering of &smc_net_ops won't be reverted.
> And if smc_nl_init() fails, &smc_net_stat_ops itself won't be reverted.
>
> This leaves wild ops in subsystem linkedlist and when another module
> tries to call register_pernet_operations() it triggers page fault:
>
> BUG: unable to handle page fault for address: fffffbfff81b964c
> RIP: 0010:register_pernet_operations+0x1b9/0x5f0
> Call Trace:
> <TASK>
> register_pernet_subsys+0x29/0x40
> ebtables_init+0x58/0x1000 [ebtables]
> ...
>
> Fixes: 194730a9beb5 ("net/smc: Make SMC statistics network namespace aware")
> Signed-off-by: Chen Zhongjin <[email protected]>

This patch looks good to me.

The subject of this patch should be in net, the prefix tag is missed.

Reviewed-by: Tony Lu <[email protected]>

> ---
> net/smc/af_smc.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
> index 3ccbf3c201cd..e12d4fa5aece 100644
> --- a/net/smc/af_smc.c
> +++ b/net/smc/af_smc.c
> @@ -3380,14 +3380,14 @@ static int __init smc_init(void)
>
> rc = register_pernet_subsys(&smc_net_stat_ops);
> if (rc)
> - return rc;
> + goto out_pernet_subsys;
>
> smc_ism_init();
> smc_clc_init();
>
> rc = smc_nl_init();
> if (rc)
> - goto out_pernet_subsys;
> + goto out_pernet_subsys_stat;
>
> rc = smc_pnet_init();
> if (rc)
> @@ -3480,6 +3480,8 @@ static int __init smc_init(void)
> smc_pnet_exit();
> out_nl:
> smc_nl_exit();
> +out_pernet_subsys_stat:
> + unregister_pernet_subsys(&smc_net_stat_ops);
> out_pernet_subsys:
> unregister_pernet_subsys(&smc_net_ops);
>
> --
> 2.17.1

2022-11-01 11:56:16

by Chen Zhongjin

[permalink] [raw]
Subject: Re: [PATCH] net/smc: Fix possible leaked pernet namespace in smc_init()

Hi,

On 2022/11/1 19:00, Tony Lu wrote:
> On Tue, Nov 01, 2022 at 05:37:22PM +0800, Chen Zhongjin wrote:
>> In smc_init(), register_pernet_subsys(&smc_net_stat_ops) is called
>> without any error handling.
>> If it fails, registering of &smc_net_ops won't be reverted.
>> And if smc_nl_init() fails, &smc_net_stat_ops itself won't be reverted.
>>
>> This leaves wild ops in subsystem linkedlist and when another module
>> tries to call register_pernet_operations() it triggers page fault:
>>
>> BUG: unable to handle page fault for address: fffffbfff81b964c
>> RIP: 0010:register_pernet_operations+0x1b9/0x5f0
>> Call Trace:
>> <TASK>
>> register_pernet_subsys+0x29/0x40
>> ebtables_init+0x58/0x1000 [ebtables]
>> ...
>>
>> Fixes: 194730a9beb5 ("net/smc: Make SMC statistics network namespace aware")
>> Signed-off-by: Chen Zhongjin <[email protected]>
> This patch looks good to me.
>
> The subject of this patch should be in net, the prefix tag is missed.

Thanks for review and remind! I will add net tag for the next time I
send patch to netdev.


Best,

Chen

>
> Reviewed-by: Tony Lu <[email protected]>
>
>> ---
>> net/smc/af_smc.c | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
>> index 3ccbf3c201cd..e12d4fa5aece 100644
>> --- a/net/smc/af_smc.c
>> +++ b/net/smc/af_smc.c
>> @@ -3380,14 +3380,14 @@ static int __init smc_init(void)
>>
>> rc = register_pernet_subsys(&smc_net_stat_ops);
>> if (rc)
>> - return rc;
>> + goto out_pernet_subsys;
>>
>> smc_ism_init();
>> smc_clc_init();
>>
>> rc = smc_nl_init();
>> if (rc)
>> - goto out_pernet_subsys;
>> + goto out_pernet_subsys_stat;
>>
>> rc = smc_pnet_init();
>> if (rc)
>> @@ -3480,6 +3480,8 @@ static int __init smc_init(void)
>> smc_pnet_exit();
>> out_nl:
>> smc_nl_exit();
>> +out_pernet_subsys_stat:
>> + unregister_pernet_subsys(&smc_net_stat_ops);
>> out_pernet_subsys:
>> unregister_pernet_subsys(&smc_net_ops);
>>
>> --
>> 2.17.1

2022-11-01 13:32:27

by Wenjia Zhang

[permalink] [raw]
Subject: Re: [PATCH] net/smc: Fix possible leaked pernet namespace in smc_init()



On 01.11.22 10:37, Chen Zhongjin wrote:
> In smc_init(), register_pernet_subsys(&smc_net_stat_ops) is called
> without any error handling.
> If it fails, registering of &smc_net_ops won't be reverted.
> And if smc_nl_init() fails, &smc_net_stat_ops itself won't be reverted.
>
> This leaves wild ops in subsystem linkedlist and when another module
> tries to call register_pernet_operations() it triggers page fault:
>
> BUG: unable to handle page fault for address: fffffbfff81b964c
> RIP: 0010:register_pernet_operations+0x1b9/0x5f0
> Call Trace:
> <TASK>
> register_pernet_subsys+0x29/0x40
> ebtables_init+0x58/0x1000 [ebtables]
> ...
>
> Fixes: 194730a9beb5 ("net/smc: Make SMC statistics network namespace aware")
> Signed-off-by: Chen Zhongjin <[email protected]>

It looks good, thank you for the effort!

Reviewed-by: Wenjia Zhang <[email protected]>
> ---
> net/smc/af_smc.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
> index 3ccbf3c201cd..e12d4fa5aece 100644
> --- a/net/smc/af_smc.c
> +++ b/net/smc/af_smc.c
> @@ -3380,14 +3380,14 @@ static int __init smc_init(void)
>
> rc = register_pernet_subsys(&smc_net_stat_ops);
> if (rc)
> - return rc;
> + goto out_pernet_subsys;
>
> smc_ism_init();
> smc_clc_init();
>
> rc = smc_nl_init();
> if (rc)
> - goto out_pernet_subsys;
> + goto out_pernet_subsys_stat;
>
> rc = smc_pnet_init();
> if (rc)
> @@ -3480,6 +3480,8 @@ static int __init smc_init(void)
> smc_pnet_exit();
> out_nl:
> smc_nl_exit();
> +out_pernet_subsys_stat:
> + unregister_pernet_subsys(&smc_net_stat_ops);
> out_pernet_subsys:
> unregister_pernet_subsys(&smc_net_ops);
>

2022-11-03 04:17:40

by patchwork-bot+netdevbpf

[permalink] [raw]
Subject: Re: [PATCH] net/smc: Fix possible leaked pernet namespace in smc_init()

Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <[email protected]>:

On Tue, 1 Nov 2022 17:37:22 +0800 you wrote:
> In smc_init(), register_pernet_subsys(&smc_net_stat_ops) is called
> without any error handling.
> If it fails, registering of &smc_net_ops won't be reverted.
> And if smc_nl_init() fails, &smc_net_stat_ops itself won't be reverted.
>
> This leaves wild ops in subsystem linkedlist and when another module
> tries to call register_pernet_operations() it triggers page fault:
>
> [...]

Here is the summary with links:
- net/smc: Fix possible leaked pernet namespace in smc_init()
https://git.kernel.org/netdev/net/c/62ff373da253

You are awesome, thank you!
--
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