From ecde3003e5205a283b46b931c729a2aecab64ba1 Mon Sep 17 00:00:00 2001 From: Vasiliy Kulikov Date: Wed, 22 May 2013 14:59:11 +0200 Subject: 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 Signed-off-by: Thomas Renninger Signed-off-by: Jiri Slaby Signed-off-by: Rafael J. Wysocki --- drivers/acpi/ec_sys.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) (limited to 'drivers') 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 #include #include +#include #include "internal.h" MODULE_AUTHOR("Thomas Renninger "); @@ -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; -- cgit v1.2.3