[PATCH] HID: hidraw: switch to using memdup_user

From: Dmitry Torokhov
Date: Wed Mar 16 2016 - 20:00:02 EST


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

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
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