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SubjectRe: [patch] pm_qos_params: cleanup: terminate a string
On Fri, Sep 03, 2010 at 02:41:06PM +0200, Dan Carpenter wrote:
> This is just a picky thing, but we pass an possibly unterminated string
> to printk if debugging is turned on. Also printk level is set to
> "debug" by pr_debug() so the "KERN_ERR" isn't used.

Picky is good. But we should probably get the other pr_debug fixed and
return -EINVAL if the strlen of the ascii_value is not bigger than 10.

thanks for finding my screw up!


>
> Signed-off-by: Dan Carpenter <error27@gmail.com>
>
> diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c
> index b7e4c36..310a51e 100644
> --- a/kernel/pm_qos_params.c
> +++ b/kernel/pm_qos_params.c
> @@ -389,10 +389,11 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
> } else if (count == 11) { /* len('0x12345678/0') */
> if (copy_from_user(ascii_value, buf, 11))
> return -EFAULT;
> + ascii_value[10] = '\0';
> x = sscanf(ascii_value, "%x", &value);
> if (x != 1)
> return -EINVAL;
> - pr_debug(KERN_ERR "%s, %d, 0x%x\n", ascii_value, x, value);
> + pr_debug("%s, %d, 0x%x\n", ascii_value, x, value);
> } else
> return -EINVAL;
>

Updated version of this patch:

--mark

Signed-off-by: mark gross <markgross@thegnar.org>

Subject: [PATCH] correct some pr_debug misuse and add a stronger parrameter check to
pm_qos_write for the ascii hex value case. Thanks to Dan Carpenter for
pointing out the problem!

---
kernel/pm_qos_params.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c
index f42d3f7..db4295a 100644
--- a/kernel/pm_qos_params.c
+++ b/kernel/pm_qos_params.c
@@ -155,7 +155,7 @@ static void update_target(int pm_qos_class)
call_notifier = 1;
atomic_set(&pm_qos_array[pm_qos_class]->target_value,
extreme_value);
- pr_debug(KERN_ERR "new target for qos %d is %d\n", pm_qos_class,
+ pr_debug("new target for qos %d is %d\n", pm_qos_class,
atomic_read(&pm_qos_array[pm_qos_class]->target_value));
}
spin_unlock_irqrestore(&pm_qos_lock, flags);
@@ -374,10 +374,12 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
} else if (count == 11) { /* len('0x12345678/0') */
if (copy_from_user(ascii_value, buf, 11))
return -EFAULT;
+ if (strlen(ascii_value) > 10)
+ return -EINVAL;
x = sscanf(ascii_value, "%x", &value);
if (x != 1)
return -EINVAL;
- pr_debug(KERN_ERR "%s, %d, 0x%x\n", ascii_value, x, value);
+ pr_debug("%s, %d, 0x%x\n", ascii_value, x, value);
} else
return -EINVAL;

--
1.7.0.4


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