* [PATCH] w1: Misuse of get_user()/put_user() reported by sparse
@ 2021-11-19 9:15 Christophe Leroy
2021-11-26 16:00 ` Greg Kroah-Hartman
0 siblings, 1 reply; 4+ messages in thread
From: Christophe Leroy @ 2021-11-19 9:15 UTC (permalink / raw)
To: Evgeniy Polyakov, Greg Kroah-Hartman
Cc: Christophe Leroy, linux-kernel, linuxppc-dev, kernel test robot
sparse warnings: (new ones prefixed by >>)
>> drivers/w1/slaves/w1_ds28e04.c:342:13: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected char [noderef] __user *_pu_addr @@ got char *buf @@
drivers/w1/slaves/w1_ds28e04.c:342:13: sparse: expected char [noderef] __user *_pu_addr
drivers/w1/slaves/w1_ds28e04.c:342:13: sparse: got char *buf
>> drivers/w1/slaves/w1_ds28e04.c:356:13: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected char const [noderef] __user *_gu_addr @@ got char const *buf @@
drivers/w1/slaves/w1_ds28e04.c:356:13: sparse: expected char const [noderef] __user *_gu_addr
drivers/w1/slaves/w1_ds28e04.c:356:13: sparse: got char const *buf
The buffer buf is a failsafe buffer in kernel space, it's not user
memory hence doesn't deserve the use of get_user() or put_user().
Access 'buf' content directly.
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/202111190526.K5vb7NWC-lkp@intel.com/T/
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
drivers/w1/slaves/w1_ds28e04.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)
diff --git a/drivers/w1/slaves/w1_ds28e04.c b/drivers/w1/slaves/w1_ds28e04.c
index e4f336111edc..d75bb16fb7a1 100644
--- a/drivers/w1/slaves/w1_ds28e04.c
+++ b/drivers/w1/slaves/w1_ds28e04.c
@@ -339,10 +339,7 @@ static BIN_ATTR_RW(pio, 1);
static ssize_t crccheck_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
- if (put_user(w1_enable_crccheck + 0x30, buf))
- return -EFAULT;
-
- return sizeof(w1_enable_crccheck);
+ return sprintf(buf, "%d", w1_enable_crccheck);
}
static ssize_t crccheck_store(struct device *dev, struct device_attribute *attr,
@@ -353,11 +350,8 @@ static ssize_t crccheck_store(struct device *dev, struct device_attribute *attr,
if (count != 1 || !buf)
return -EINVAL;
- if (get_user(val, buf))
- return -EFAULT;
-
/* convert to decimal */
- val = val - 0x30;
+ val = *buf - 0x30;
if (val != 0 && val != 1)
return -EINVAL;
--
2.33.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] w1: Misuse of get_user()/put_user() reported by sparse
2021-11-19 9:15 [PATCH] w1: Misuse of get_user()/put_user() reported by sparse Christophe Leroy
@ 2021-11-26 16:00 ` Greg Kroah-Hartman
2021-11-26 16:10 ` Christophe Leroy
0 siblings, 1 reply; 4+ messages in thread
From: Greg Kroah-Hartman @ 2021-11-26 16:00 UTC (permalink / raw)
To: Christophe Leroy
Cc: Evgeniy Polyakov, linux-kernel, linuxppc-dev, kernel test robot
On Fri, Nov 19, 2021 at 10:15:09AM +0100, Christophe Leroy wrote:
> sparse warnings: (new ones prefixed by >>)
> >> drivers/w1/slaves/w1_ds28e04.c:342:13: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected char [noderef] __user *_pu_addr @@ got char *buf @@
> drivers/w1/slaves/w1_ds28e04.c:342:13: sparse: expected char [noderef] __user *_pu_addr
> drivers/w1/slaves/w1_ds28e04.c:342:13: sparse: got char *buf
> >> drivers/w1/slaves/w1_ds28e04.c:356:13: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected char const [noderef] __user *_gu_addr @@ got char const *buf @@
> drivers/w1/slaves/w1_ds28e04.c:356:13: sparse: expected char const [noderef] __user *_gu_addr
> drivers/w1/slaves/w1_ds28e04.c:356:13: sparse: got char const *buf
>
> The buffer buf is a failsafe buffer in kernel space, it's not user
> memory hence doesn't deserve the use of get_user() or put_user().
>
> Access 'buf' content directly.
>
> Reported-by: kernel test robot <lkp@intel.com>
> Link: https://lore.kernel.org/lkml/202111190526.K5vb7NWC-lkp@intel.com/T/
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
> drivers/w1/slaves/w1_ds28e04.c | 10 ++--------
> 1 file changed, 2 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/w1/slaves/w1_ds28e04.c b/drivers/w1/slaves/w1_ds28e04.c
> index e4f336111edc..d75bb16fb7a1 100644
> --- a/drivers/w1/slaves/w1_ds28e04.c
> +++ b/drivers/w1/slaves/w1_ds28e04.c
> @@ -339,10 +339,7 @@ static BIN_ATTR_RW(pio, 1);
> static ssize_t crccheck_show(struct device *dev, struct device_attribute *attr,
> char *buf)
> {
> - if (put_user(w1_enable_crccheck + 0x30, buf))
> - return -EFAULT;
> -
> - return sizeof(w1_enable_crccheck);
> + return sprintf(buf, "%d", w1_enable_crccheck);
This should be sysfs_emit(), right?
> }
>
> static ssize_t crccheck_store(struct device *dev, struct device_attribute *attr,
> @@ -353,11 +350,8 @@ static ssize_t crccheck_store(struct device *dev, struct device_attribute *attr,
> if (count != 1 || !buf)
> return -EINVAL;
>
> - if (get_user(val, buf))
> - return -EFAULT;
> -
> /* convert to decimal */
> - val = val - 0x30;
> + val = *buf - 0x30;
Why not use a proper function that can parse a string and turn it into a
number?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] w1: Misuse of get_user()/put_user() reported by sparse
2021-11-26 16:00 ` Greg Kroah-Hartman
@ 2021-11-26 16:10 ` Christophe Leroy
2021-11-26 16:24 ` Greg Kroah-Hartman
0 siblings, 1 reply; 4+ messages in thread
From: Christophe Leroy @ 2021-11-26 16:10 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Evgeniy Polyakov, linux-kernel, linuxppc-dev, kernel test robot
Le 26/11/2021 à 17:00, Greg Kroah-Hartman a écrit :
> On Fri, Nov 19, 2021 at 10:15:09AM +0100, Christophe Leroy wrote:
>> sparse warnings: (new ones prefixed by >>)
>>>> drivers/w1/slaves/w1_ds28e04.c:342:13: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected char [noderef] __user *_pu_addr @@ got char *buf @@
>> drivers/w1/slaves/w1_ds28e04.c:342:13: sparse: expected char [noderef] __user *_pu_addr
>> drivers/w1/slaves/w1_ds28e04.c:342:13: sparse: got char *buf
>>>> drivers/w1/slaves/w1_ds28e04.c:356:13: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected char const [noderef] __user *_gu_addr @@ got char const *buf @@
>> drivers/w1/slaves/w1_ds28e04.c:356:13: sparse: expected char const [noderef] __user *_gu_addr
>> drivers/w1/slaves/w1_ds28e04.c:356:13: sparse: got char const *buf
>>
>> The buffer buf is a failsafe buffer in kernel space, it's not user
>> memory hence doesn't deserve the use of get_user() or put_user().
>>
>> Access 'buf' content directly.
>>
>> Reported-by: kernel test robot <lkp@intel.com>
>> Link: https://lore.kernel.org/lkml/202111190526.K5vb7NWC-lkp@intel.com/T/
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>> drivers/w1/slaves/w1_ds28e04.c | 10 ++--------
>> 1 file changed, 2 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/w1/slaves/w1_ds28e04.c b/drivers/w1/slaves/w1_ds28e04.c
>> index e4f336111edc..d75bb16fb7a1 100644
>> --- a/drivers/w1/slaves/w1_ds28e04.c
>> +++ b/drivers/w1/slaves/w1_ds28e04.c
>> @@ -339,10 +339,7 @@ static BIN_ATTR_RW(pio, 1);
>> static ssize_t crccheck_show(struct device *dev, struct device_attribute *attr,
>> char *buf)
>> {
>> - if (put_user(w1_enable_crccheck + 0x30, buf))
>> - return -EFAULT;
>> -
>> - return sizeof(w1_enable_crccheck);
>> + return sprintf(buf, "%d", w1_enable_crccheck);
>
> This should be sysfs_emit(), right?
Ok
>
>> }
>>
>> static ssize_t crccheck_store(struct device *dev, struct device_attribute *attr,
>> @@ -353,11 +350,8 @@ static ssize_t crccheck_store(struct device *dev, struct device_attribute *attr,
>> if (count != 1 || !buf)
>> return -EINVAL;
>>
>> - if (get_user(val, buf))
>> - return -EFAULT;
>> -
>> /* convert to decimal */
>> - val = val - 0x30;
>> + val = *buf - 0x30;
>
> Why not use a proper function that can parse a string and turn it into a
> number?
I wanted to keep the change minimal. But I can also replace it with some
scanf.
But don't we have any generic function to read and store a bool after all ?
Thanks
Christophe
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] w1: Misuse of get_user()/put_user() reported by sparse
2021-11-26 16:10 ` Christophe Leroy
@ 2021-11-26 16:24 ` Greg Kroah-Hartman
0 siblings, 0 replies; 4+ messages in thread
From: Greg Kroah-Hartman @ 2021-11-26 16:24 UTC (permalink / raw)
To: Christophe Leroy
Cc: Evgeniy Polyakov, linux-kernel, linuxppc-dev, kernel test robot
On Fri, Nov 26, 2021 at 05:10:46PM +0100, Christophe Leroy wrote:
>
>
> Le 26/11/2021 à 17:00, Greg Kroah-Hartman a écrit :
> > On Fri, Nov 19, 2021 at 10:15:09AM +0100, Christophe Leroy wrote:
> > > sparse warnings: (new ones prefixed by >>)
> > > > > drivers/w1/slaves/w1_ds28e04.c:342:13: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected char [noderef] __user *_pu_addr @@ got char *buf @@
> > > drivers/w1/slaves/w1_ds28e04.c:342:13: sparse: expected char [noderef] __user *_pu_addr
> > > drivers/w1/slaves/w1_ds28e04.c:342:13: sparse: got char *buf
> > > > > drivers/w1/slaves/w1_ds28e04.c:356:13: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected char const [noderef] __user *_gu_addr @@ got char const *buf @@
> > > drivers/w1/slaves/w1_ds28e04.c:356:13: sparse: expected char const [noderef] __user *_gu_addr
> > > drivers/w1/slaves/w1_ds28e04.c:356:13: sparse: got char const *buf
> > >
> > > The buffer buf is a failsafe buffer in kernel space, it's not user
> > > memory hence doesn't deserve the use of get_user() or put_user().
> > >
> > > Access 'buf' content directly.
> > >
> > > Reported-by: kernel test robot <lkp@intel.com>
> > > Link: https://lore.kernel.org/lkml/202111190526.K5vb7NWC-lkp@intel.com/T/
> > > Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> > > ---
> > > drivers/w1/slaves/w1_ds28e04.c | 10 ++--------
> > > 1 file changed, 2 insertions(+), 8 deletions(-)
> > >
> > > diff --git a/drivers/w1/slaves/w1_ds28e04.c b/drivers/w1/slaves/w1_ds28e04.c
> > > index e4f336111edc..d75bb16fb7a1 100644
> > > --- a/drivers/w1/slaves/w1_ds28e04.c
> > > +++ b/drivers/w1/slaves/w1_ds28e04.c
> > > @@ -339,10 +339,7 @@ static BIN_ATTR_RW(pio, 1);
> > > static ssize_t crccheck_show(struct device *dev, struct device_attribute *attr,
> > > char *buf)
> > > {
> > > - if (put_user(w1_enable_crccheck + 0x30, buf))
> > > - return -EFAULT;
> > > -
> > > - return sizeof(w1_enable_crccheck);
> > > + return sprintf(buf, "%d", w1_enable_crccheck);
> >
> > This should be sysfs_emit(), right?
>
> Ok
>
> >
> > > }
> > > static ssize_t crccheck_store(struct device *dev, struct device_attribute *attr,
> > > @@ -353,11 +350,8 @@ static ssize_t crccheck_store(struct device *dev, struct device_attribute *attr,
> > > if (count != 1 || !buf)
> > > return -EINVAL;
> > > - if (get_user(val, buf))
> > > - return -EFAULT;
> > > -
> > > /* convert to decimal */
> > > - val = val - 0x30;
> > > + val = *buf - 0x30;
> >
> > Why not use a proper function that can parse a string and turn it into a
> > number?
>
> I wanted to keep the change minimal. But I can also replace it with some
> scanf.
>
> But don't we have any generic function to read and store a bool after all ?
Yes we do, please use kstrtobool().
thanks,
greg k-h
^ permalink raw reply [flat|nested] 4+ messages in thread
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2021-11-19 9:15 [PATCH] w1: Misuse of get_user()/put_user() reported by sparse Christophe Leroy
2021-11-26 16:00 ` Greg Kroah-Hartman
2021-11-26 16:10 ` Christophe Leroy
2021-11-26 16:24 ` Greg Kroah-Hartman
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