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Commit ecde3003 authored by Vasiliy Kulikov's avatar Vasiliy Kulikov Committed by Rafael J. Wysocki
Browse files

ACPI / EC: access user space with get_user()/put_user() 



User space pointer may not be dereferenced. Use get_user()/put_user()
instead and check their return codes.

Signed-off-by: default avatarVasiliy Kulikov <segooon@gmail.com>
Signed-off-by: default avatarThomas Renninger <trenn@suse.de>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 7d132055

drivers/acpi/ec_sys.c

+14 −4
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 
#include <linux/acpi.h>

#include <linux/debugfs.h>

#include <linux/module.h>

#include <linux/uaccess.h>

#include "internal.h"



MODULE_AUTHOR("Thomas Renninger <trenn@suse.de>");
@@ -34,7 +35,6 @@ static ssize_t acpi_ec_read_io(struct file *f, char __user *buf, 
	 * struct acpi_ec *ec = ((struct seq_file *)f->private_data)->private;

	 */

	unsigned int size = EC_SPACE_SIZE;

	u8 *data = (u8 *) buf;

	loff_t init_off = *off;

	int err = 0;
@@ -47,9 +47,15 @@ static ssize_t acpi_ec_read_io(struct file *f, char __user *buf, 
		size = count;



	while (size) {

		err = ec_read(*off, &data[*off - init_off]);

		u8 byte_read;

		err = ec_read(*off, &byte_read);

		if (err)

			return err;

		if (put_user(byte_read, buf + *off - init_off)) {

			if (*off - init_off)

				return *off - init_off; /* partial read */

			return -EFAULT;

		}

		*off += 1;

		size--;

	}
@@ -65,7 +71,6 @@ static ssize_t acpi_ec_write_io(struct file *f, const char __user *buf, 


	unsigned int size = count;

	loff_t init_off = *off;

	u8 *data = (u8 *) buf;

	int err = 0;



	if (*off >= EC_SPACE_SIZE)
@@ -76,7 +81,12 @@ static ssize_t acpi_ec_write_io(struct file *f, const char __user *buf, 
	}



	while (size) {

		u8 byte_write = data[*off - init_off];

		u8 byte_write;

		if (get_user(byte_write, buf + *off - init_off)) {

			if (*off - init_off)

				return *off - init_off; /* partial write */

			return -EFAULT;

		}

		err = ec_write(*off, byte_write);

		if (err)

			return err;