[PATCH] HID: hidraw: switch to using memdup_user

[PATCH] HID: hidraw: switch to using memdup_user

[Dmitry Torokhov]

Instead of open-coding memory allocation and copying form user memory
sequence let's use memdup_user().

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/hid/hidraw.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
index 9c2d7c2..b9a76e3 100644
--- a/drivers/hid/hidraw.c
+++ b/drivers/hid/hidraw.c
@@ -34,6 +34,7 @@
 #include <linux/hid.h>
 #include <linux/mutex.h>
 #include <linux/sched.h>
+#include <linux/string.h>
 
 #include <linux/hidraw.h>
 
@@ -123,7 +124,6 @@ static ssize_t hidraw_send_report(struct file *file, const char __user *buffer,
 
 	dev = hidraw_table[minor]->hid;
 
-
 	if (count > HID_MAX_BUFFER_SIZE) {
 		hid_warn(dev, "pid %d passed too large report\n",
 			 task_pid_nr(current));
@@ -138,17 +138,12 @@ static ssize_t hidraw_send_report(struct file *file, const char __user *buffer,
 		goto out;
 	}
 
-	buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
-	if (!buf) {
-		ret = -ENOMEM;
+	buf = memdup_user(buffer, count);
+	if (IS_ERR(buf)) {
+		ret = PTR_ERR(buf);
 		goto out;
 	}
 
-	if (copy_from_user(buf, buffer, count)) {
-		ret = -EFAULT;
-		goto out_free;
-	}
-
 	if ((report_type == HID_OUTPUT_REPORT) &&
 	    !(dev->quirks & HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP)) {
 		ret = hid_hw_output_report(dev, buf, count);
-- 
2.7.0.rc3.207.g0ac5344


-- 
Dmitry

Re: [PATCH] HID: hidraw: switch to using memdup_user

[Benjamin Tissoires]

On Mar 16 2016 or thereabouts, Dmitry Torokhov wrote:
> Instead of open-coding memory allocation and copying form user memory
> sequence let's use memdup_user().
> 
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> ---

Works for me:
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

Cheers,
Benjamin

>  drivers/hid/hidraw.c | 13 ++++---------
>  1 file changed, 4 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
> index 9c2d7c2..b9a76e3 100644
> --- a/drivers/hid/hidraw.c
> +++ b/drivers/hid/hidraw.c
> @@ -34,6 +34,7 @@
>  #include <linux/hid.h>
>  #include <linux/mutex.h>
>  #include <linux/sched.h>
> +#include <linux/string.h>
>  
>  #include <linux/hidraw.h>
>  
> @@ -123,7 +124,6 @@ static ssize_t hidraw_send_report(struct file *file, const char __user *buffer,
>  
>  	dev = hidraw_table[minor]->hid;
>  
> -
>  	if (count > HID_MAX_BUFFER_SIZE) {
>  		hid_warn(dev, "pid %d passed too large report\n",
>  			 task_pid_nr(current));
> @@ -138,17 +138,12 @@ static ssize_t hidraw_send_report(struct file *file, const char __user *buffer,
>  		goto out;
>  	}
>  
> -	buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
> -	if (!buf) {
> -		ret = -ENOMEM;
> +	buf = memdup_user(buffer, count);
> +	if (IS_ERR(buf)) {
> +		ret = PTR_ERR(buf);
>  		goto out;
>  	}
>  
> -	if (copy_from_user(buf, buffer, count)) {
> -		ret = -EFAULT;
> -		goto out_free;
> -	}
> -
>  	if ((report_type == HID_OUTPUT_REPORT) &&
>  	    !(dev->quirks & HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP)) {
>  		ret = hid_hw_output_report(dev, buf, count);
> -- 
> 2.7.0.rc3.207.g0ac5344
> 
> 
> -- 
> Dmitry

Re: [PATCH] HID: hidraw: switch to using memdup_user

[Jiri Kosina]

On Wed, 16 Mar 2016, Dmitry Torokhov wrote:

> Instead of open-coding memory allocation and copying form user memory
> sequence let's use memdup_user().

Makes sense. Applied, thanks.

-- 
Jiri Kosina
SUSE Labs