* [PATCH v2] w1: Misuse of get_user()/put_user() reported by sparse
@ 2021-11-26 16:47 Christophe Leroy
2021-11-26 16:54 ` Greg Kroah-Hartman
0 siblings, 1 reply; 4+ messages in thread
From: Christophe Leroy @ 2021-11-26 16:47 UTC (permalink / raw)
To: Evgeniy Polyakov, Greg Kroah-Hartman
Cc: linuxppc-dev, linux-kernel, 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>
---
v2: Use sysfs_emit() and kstrtobool()
---
drivers/w1/slaves/w1_ds28e04.c | 25 +++----------------------
1 file changed, 3 insertions(+), 22 deletions(-)
diff --git a/drivers/w1/slaves/w1_ds28e04.c b/drivers/w1/slaves/w1_ds28e04.c
index e4f336111edc..98f80f412cfd 100644
--- a/drivers/w1/slaves/w1_ds28e04.c
+++ b/drivers/w1/slaves/w1_ds28e04.c
@@ -32,7 +32,7 @@ static int w1_strong_pullup = 1;
module_param_named(strong_pullup, w1_strong_pullup, int, 0);
/* enable/disable CRC checking on DS28E04-100 memory accesses */
-static char w1_enable_crccheck = 1;
+static bool w1_enable_crccheck = true;
#define W1_EEPROM_SIZE 512
#define W1_PAGE_COUNT 16
@@ -339,32 +339,13 @@ 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 sysfs_emit(buf, "%d\n", w1_enable_crccheck);
}
static ssize_t crccheck_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
- char val;
-
- if (count != 1 || !buf)
- return -EINVAL;
-
- if (get_user(val, buf))
- return -EFAULT;
-
- /* convert to decimal */
- val = val - 0x30;
- if (val != 0 && val != 1)
- return -EINVAL;
-
- /* set the new value */
- w1_enable_crccheck = val;
-
- return sizeof(w1_enable_crccheck);
+ return kstrtobool(buf, &w1_enable_crccheck) ? : count;
}
static DEVICE_ATTR_RW(crccheck);
--
2.33.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] w1: Misuse of get_user()/put_user() reported by sparse
2021-11-26 16:47 [PATCH v2] w1: Misuse of get_user()/put_user() reported by sparse Christophe Leroy
@ 2021-11-26 16:54 ` Greg Kroah-Hartman
2021-11-26 16:57 ` Christophe Leroy
0 siblings, 1 reply; 4+ messages in thread
From: Greg Kroah-Hartman @ 2021-11-26 16:54 UTC (permalink / raw)
To: Christophe Leroy
Cc: Evgeniy Polyakov, linuxppc-dev, linux-kernel, kernel test robot
On Fri, Nov 26, 2021 at 05:47:58PM +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>
> ---
> v2: Use sysfs_emit() and kstrtobool()
> ---
> drivers/w1/slaves/w1_ds28e04.c | 25 +++----------------------
> 1 file changed, 3 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/w1/slaves/w1_ds28e04.c b/drivers/w1/slaves/w1_ds28e04.c
> index e4f336111edc..98f80f412cfd 100644
> --- a/drivers/w1/slaves/w1_ds28e04.c
> +++ b/drivers/w1/slaves/w1_ds28e04.c
> @@ -32,7 +32,7 @@ static int w1_strong_pullup = 1;
> module_param_named(strong_pullup, w1_strong_pullup, int, 0);
>
> /* enable/disable CRC checking on DS28E04-100 memory accesses */
> -static char w1_enable_crccheck = 1;
> +static bool w1_enable_crccheck = true;
>
> #define W1_EEPROM_SIZE 512
> #define W1_PAGE_COUNT 16
> @@ -339,32 +339,13 @@ 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 sysfs_emit(buf, "%d\n", w1_enable_crccheck);
> }
>
> static ssize_t crccheck_store(struct device *dev, struct device_attribute *attr,
> const char *buf, size_t count)
> {
> - char val;
> -
> - if (count != 1 || !buf)
> - return -EINVAL;
> -
> - if (get_user(val, buf))
> - return -EFAULT;
> -
> - /* convert to decimal */
> - val = val - 0x30;
> - if (val != 0 && val != 1)
> - return -EINVAL;
> -
> - /* set the new value */
> - w1_enable_crccheck = val;
> -
> - return sizeof(w1_enable_crccheck);
> + return kstrtobool(buf, &w1_enable_crccheck) ? : count;
Please spell this line out, using ? : is unreadable at times.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] w1: Misuse of get_user()/put_user() reported by sparse
2021-11-26 16:54 ` Greg Kroah-Hartman
@ 2021-11-26 16:57 ` Christophe Leroy
2021-11-26 17:02 ` Greg Kroah-Hartman
0 siblings, 1 reply; 4+ messages in thread
From: Christophe Leroy @ 2021-11-26 16:57 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Evgeniy Polyakov, linuxppc-dev, linux-kernel, kernel test robot
Le 26/11/2021 à 17:54, Greg Kroah-Hartman a écrit :
> On Fri, Nov 26, 2021 at 05:47:58PM +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>
>> ---
>> v2: Use sysfs_emit() and kstrtobool()
>> ---
>> drivers/w1/slaves/w1_ds28e04.c | 25 +++----------------------
>> 1 file changed, 3 insertions(+), 22 deletions(-)
>>
>> diff --git a/drivers/w1/slaves/w1_ds28e04.c b/drivers/w1/slaves/w1_ds28e04.c
>> index e4f336111edc..98f80f412cfd 100644
>> --- a/drivers/w1/slaves/w1_ds28e04.c
>> +++ b/drivers/w1/slaves/w1_ds28e04.c
>> @@ -32,7 +32,7 @@ static int w1_strong_pullup = 1;
>> module_param_named(strong_pullup, w1_strong_pullup, int, 0);
>>
>> /* enable/disable CRC checking on DS28E04-100 memory accesses */
>> -static char w1_enable_crccheck = 1;
>> +static bool w1_enable_crccheck = true;
>>
>> #define W1_EEPROM_SIZE 512
>> #define W1_PAGE_COUNT 16
>> @@ -339,32 +339,13 @@ 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 sysfs_emit(buf, "%d\n", w1_enable_crccheck);
>> }
>>
>> static ssize_t crccheck_store(struct device *dev, struct device_attribute *attr,
>> const char *buf, size_t count)
>> {
>> - char val;
>> -
>> - if (count != 1 || !buf)
>> - return -EINVAL;
>> -
>> - if (get_user(val, buf))
>> - return -EFAULT;
>> -
>> - /* convert to decimal */
>> - val = val - 0x30;
>> - if (val != 0 && val != 1)
>> - return -EINVAL;
>> -
>> - /* set the new value */
>> - w1_enable_crccheck = val;
>> -
>> - return sizeof(w1_enable_crccheck);
>> + return kstrtobool(buf, &w1_enable_crccheck) ? : count;
>
> Please spell this line out, using ? : is unreadable at times.
>
You prefer something like:
int err = kstrtobool(buf, &w1_enable_crccheck);
return err ? err : count;
Or
int err = kstrtobool(buf, &w1_enable_crccheck);
if (err)
return err;
return count;
?
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] w1: Misuse of get_user()/put_user() reported by sparse
2021-11-26 16:57 ` Christophe Leroy
@ 2021-11-26 17:02 ` Greg Kroah-Hartman
0 siblings, 0 replies; 4+ messages in thread
From: Greg Kroah-Hartman @ 2021-11-26 17:02 UTC (permalink / raw)
To: Christophe Leroy
Cc: Evgeniy Polyakov, linuxppc-dev, linux-kernel, kernel test robot
On Fri, Nov 26, 2021 at 05:57:58PM +0100, Christophe Leroy wrote:
>
>
> Le 26/11/2021 à 17:54, Greg Kroah-Hartman a écrit :
> > On Fri, Nov 26, 2021 at 05:47:58PM +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>
> > > ---
> > > v2: Use sysfs_emit() and kstrtobool()
> > > ---
> > > drivers/w1/slaves/w1_ds28e04.c | 25 +++----------------------
> > > 1 file changed, 3 insertions(+), 22 deletions(-)
> > >
> > > diff --git a/drivers/w1/slaves/w1_ds28e04.c b/drivers/w1/slaves/w1_ds28e04.c
> > > index e4f336111edc..98f80f412cfd 100644
> > > --- a/drivers/w1/slaves/w1_ds28e04.c
> > > +++ b/drivers/w1/slaves/w1_ds28e04.c
> > > @@ -32,7 +32,7 @@ static int w1_strong_pullup = 1;
> > > module_param_named(strong_pullup, w1_strong_pullup, int, 0);
> > > /* enable/disable CRC checking on DS28E04-100 memory accesses */
> > > -static char w1_enable_crccheck = 1;
> > > +static bool w1_enable_crccheck = true;
> > > #define W1_EEPROM_SIZE 512
> > > #define W1_PAGE_COUNT 16
> > > @@ -339,32 +339,13 @@ 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 sysfs_emit(buf, "%d\n", w1_enable_crccheck);
> > > }
> > > static ssize_t crccheck_store(struct device *dev, struct device_attribute *attr,
> > > const char *buf, size_t count)
> > > {
> > > - char val;
> > > -
> > > - if (count != 1 || !buf)
> > > - return -EINVAL;
> > > -
> > > - if (get_user(val, buf))
> > > - return -EFAULT;
> > > -
> > > - /* convert to decimal */
> > > - val = val - 0x30;
> > > - if (val != 0 && val != 1)
> > > - return -EINVAL;
> > > -
> > > - /* set the new value */
> > > - w1_enable_crccheck = val;
> > > -
> > > - return sizeof(w1_enable_crccheck);
> > > + return kstrtobool(buf, &w1_enable_crccheck) ? : count;
> >
> > Please spell this line out, using ? : is unreadable at times.
> >
>
> You prefer something like:
>
> int err = kstrtobool(buf, &w1_enable_crccheck);
>
> return err ? err : count;
>
>
> Or
>
> int err = kstrtobool(buf, &w1_enable_crccheck);
>
> if (err)
> return err;
>
> return count;
This one. Write code for people to read first, compiler second.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 4+ messages in thread
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Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2021-11-26 16:47 [PATCH v2] w1: Misuse of get_user()/put_user() reported by sparse Christophe Leroy
2021-11-26 16:54 ` Greg Kroah-Hartman
2021-11-26 16:57 ` Christophe Leroy
2021-11-26 17:02 ` Greg Kroah-Hartman
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