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authorVasiliy Kulikov <segooon@gmail.com>2013-05-22 14:59:11 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-06-19 23:29:20 +0200
commitecde3003e5205a283b46b931c729a2aecab64ba1 (patch)
treee76f86792706f5b3be85e7ac73fdb9b96cd532c5 /drivers/acpi/ec_sys.c
parent7d132055814ef17a6c7b69f342244c410a5e000f (diff)
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: Vasiliy Kulikov <segooon@gmail.com> Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/ec_sys.c')
-rw-r--r--drivers/acpi/ec_sys.c18
1 files changed, 14 insertions, 4 deletions
diff --git a/drivers/acpi/ec_sys.c b/drivers/acpi/ec_sys.c
index 7586544fddb..4e7b798900f 100644
--- a/drivers/acpi/ec_sys.c
+++ b/drivers/acpi/ec_sys.c
@@ -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;