diff options
| author | Vasiliy Kulikov <segooon@gmail.com> | 2013-05-22 14:59:11 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-06-19 23:29:20 +0200 |
| commit | ecde3003e5205a283b46b931c729a2aecab64ba1 (patch) | |
| tree | e76f86792706f5b3be85e7ac73fdb9b96cd532c5 | |
| parent | 7d132055814ef17a6c7b69f342244c410a5e000f (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>
| -rw-r--r-- | drivers/acpi/ec_sys.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/drivers/acpi/ec_sys.c b/drivers/acpi/ec_sys.c index 7586544fddb4..4e7b798900f2 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; |