2022-07-16 10:33:53

by Gaosheng Cui

Subject: [PATCH -next,v2] nvmem: core: Fix memleak in nvmem_register()

dev_set_name will alloc memory for nvmem->dev.kobj.name in
nvmem_register, when nvmem_validate_keepouts failed, nvmem's
memory will be freed and return, but nobody will free memory
for nvmem->dev.kobj.name, there will be memleak, so moving
dev_set_name after nvmem_validate_keepouts to fix it.

Fixes: de0534df9347 ("nvmem: core: fix error handling while validating keepout regions")
Signed-off-by: Gaosheng Cui <[email protected]>
---
drivers/nvmem/core.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 1e3c754efd0d..a5d75edf509d 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -808,20 +808,6 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
else if (!config->no_of_node)
nvmem->dev.of_node = config->dev->of_node;

- switch (config->id) {
- case NVMEM_DEVID_NONE:
- dev_set_name(&nvmem->dev, "%s", config->name);
- break;
- case NVMEM_DEVID_AUTO:
- dev_set_name(&nvmem->dev, "%s%d", config->name, nvmem->id);
- break;
- default:
- dev_set_name(&nvmem->dev, "%s%d",
- config->name ? : "nvmem",
- config->name ? config->id : nvmem->id);
- break;
- }
-
nvmem->read_only = device_property_present(config->dev, "read-only") ||
config->read_only || !nvmem->reg_write;

@@ -838,6 +824,20 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
}
}

+ switch (config->id) {
+ case NVMEM_DEVID_NONE:
+ dev_set_name(&nvmem->dev, "%s", config->name);
+ break;
+ case NVMEM_DEVID_AUTO:
+ dev_set_name(&nvmem->dev, "%s%d", config->name, nvmem->id);
+ break;
+ default:
+ dev_set_name(&nvmem->dev, "%s%d",
+ config->name ? : "nvmem",
+ config->name ? config->id : nvmem->id);
+ break;
+ }
+
dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);

rval = device_register(&nvmem->dev);
--
2.25.1

2022-07-18 12:27:01

by Srinivas Kandagatla

Subject: Re: [PATCH -next,v2] nvmem: core: Fix memleak in nvmem_register()

On 16/07/2022 10:52, Gaosheng Cui wrote:
> dev_set_name will alloc memory for nvmem->dev.kobj.name in
> nvmem_register, when nvmem_validate_keepouts failed, nvmem's
> memory will be freed and return, but nobody will free memory
> for nvmem->dev.kobj.name, there will be memleak, so moving
> dev_set_name after nvmem_validate_keepouts to fix it.
>
> Fixes: de0534df9347 ("nvmem: core: fix error handling while validating keepout regions")
> Signed-off-by: Gaosheng Cui <[email protected]>
> ---
> drivers/nvmem/core.c | 28 ++++++++++++++--------------
> 1 file changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
> index 1e3c754efd0d..a5d75edf509d 100644
> --- a/drivers/nvmem/core.c
> +++ b/drivers/nvmem/core.c
> @@ -808,20 +808,6 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
> else if (!config->no_of_node)
> nvmem->dev.of_node = config->dev->of_node;
>
> - switch (config->id) {
> - case NVMEM_DEVID_NONE:
> - dev_set_name(&nvmem->dev, "%s", config->name);
> - break;
> - case NVMEM_DEVID_AUTO:
> - dev_set_name(&nvmem->dev, "%s%d", config->name, nvmem->id);
> - break;
> - default:
> - dev_set_name(&nvmem->dev, "%s%d",
> - config->name ? : "nvmem",
> - config->name ? config->id : nvmem->id);
> - break;
> - }
> -
> nvmem->read_only = device_property_present(config->dev, "read-only") ||
> config->read_only || !nvmem->reg_write;
>
> @@ -838,6 +824,20 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
> }
> }
>
> + switch (config->id) {
> + case NVMEM_DEVID_NONE:
> + dev_set_name(&nvmem->dev, "%s", config->name);
> + break;
> + case NVMEM_DEVID_AUTO:
> + dev_set_name(&nvmem->dev, "%s%d", config->name, nvmem->id);
> + break;
> + default:
> + dev_set_name(&nvmem->dev, "%s%d",
> + config->name ? : "nvmem",
> + config->name ? config->id : nvmem->id);
> + break;
> + }
> +
The issue with this approach is that dev_err messages in
nvmem_validate_keepouts() will show up without device name setup.

I think better option is to move nvmem_validate_keepouts() after
device_register() and let the device core deal with cleaning name in
error cases.

--srini

> dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);
>
> rval = device_register(&nvmem->dev);

2022-07-18 13:15:21

by Gaosheng Cui

Subject: Re: [PATCH -next,v2] nvmem: core: Fix memleak in nvmem_register()

Thanks for your ideas,

I have made another patch, moving nvmem_validate_keepouts() after
device_register() and let the device core deal with cleaning name in
error cases, it's a better option for the issue.

Thanks,

在 2022/7/18 19:44, Srinivas Kandagatla 写道:
>
>
> On 16/07/2022 10:52, Gaosheng Cui wrote:
>> dev_set_name will alloc memory for nvmem->dev.kobj.name in
>> nvmem_register, when nvmem_validate_keepouts failed, nvmem's
>> memory will be freed and return, but nobody will free memory
>> for nvmem->dev.kobj.name, there will be memleak, so moving
>> dev_set_name after nvmem_validate_keepouts to fix it.
>>
>> Fixes: de0534df9347 ("nvmem: core: fix error handling while
>> validating keepout regions")
>> Signed-off-by: Gaosheng Cui <[email protected]>
>> ---
>>   drivers/nvmem/core.c | 28 ++++++++++++++--------------
>>   1 file changed, 14 insertions(+), 14 deletions(-)
>>
>> diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
>> index 1e3c754efd0d..a5d75edf509d 100644
>> --- a/drivers/nvmem/core.c
>> +++ b/drivers/nvmem/core.c
>> @@ -808,20 +808,6 @@ struct nvmem_device *nvmem_register(const struct
>> nvmem_config *config)
>>       else if (!config->no_of_node)
>>           nvmem->dev.of_node = config->dev->of_node;
>>   -    switch (config->id) {
>> -    case NVMEM_DEVID_NONE:
>> -        dev_set_name(&nvmem->dev, "%s", config->name);
>> -        break;
>> -    case NVMEM_DEVID_AUTO:
>> -        dev_set_name(&nvmem->dev, "%s%d", config->name, nvmem->id);
>> -        break;
>> -    default:
>> -        dev_set_name(&nvmem->dev, "%s%d",
>> -                 config->name ? : "nvmem",
>> -                 config->name ? config->id : nvmem->id);
>> -        break;
>> -    }
>> -
>>       nvmem->read_only = device_property_present(config->dev,
>> "read-only") ||
>>                  config->read_only || !nvmem->reg_write;
>>   @@ -838,6 +824,20 @@ struct nvmem_device *nvmem_register(const
>> struct nvmem_config *config)
>>           }
>>       }
>>   +    switch (config->id) {
>> +    case NVMEM_DEVID_NONE:
>> +        dev_set_name(&nvmem->dev, "%s", config->name);
>> +        break;
>> +    case NVMEM_DEVID_AUTO:
>> +        dev_set_name(&nvmem->dev, "%s%d", config->name, nvmem->id);
>> +        break;
>> +    default:
>> +        dev_set_name(&nvmem->dev, "%s%d",
>> +                 config->name ? : "nvmem",
>> +                 config->name ? config->id : nvmem->id);
>> +        break;
>> +    }
>> +
> The issue with this approach is that dev_err messages in
> nvmem_validate_keepouts() will show up without device name setup.
>
> I think better option is to move nvmem_validate_keepouts() after
> device_register() and let the device core deal with cleaning name in
> error cases.
>
> --srini
>
>>       dev_dbg(&nvmem->dev, "Registering nvmem device %s\n",
>> config->name);
>>         rval = device_register(&nvmem->dev);
> .