Subject: ACPI: fix acpi fan state set error
From: Yi Yang <[EMAIL PROTECTED]>
Under /proc/acpi, there is a fan control interface, a user can
set 0 or 3 to /proc/acpi/fan/*/state, 0 denotes D0 state, 3
denotes D3 state, but in current implementation, a user can
set a fan to D1 state by any char excluding '1', '2' and '3'.
For example:
[EMAIL PROTECTED] acpi]# cat /proc/acpi/fan/C31B/state
status: off
[EMAIL PROTECTED] acpi]# echo "" > /proc/acpi/fan/C31B/state
[EMAIL PROTECTED] acpi]# cat /proc/acpi/fan/C31B/state
status: on
[EMAIL PROTECTED] acpi]# echo "3" > /proc/acpi/fan/C31B/state
[EMAIL PROTECTED] acpi]# cat /proc/acpi/fan/C31B/state
status: off
[EMAIL PROTECTED] acpi]# echo "xxxxx" > /proc/acpi/fan/C31B/state
[EMAIL PROTECTED] acpi]# cat /proc/acpi/fan/C31B/state
status: on
Obviously, such inputs as "" and "xxxxx" are invalid for fan state.
This patch fixes this issue, it strictly limits fan state only to
accept 0, 1, 2 and 3, any other inputs are invalid.
Before applying this patch, the test result is:
[EMAIL PROTECTED] acpi]# cat /proc/acpi/fan/C31B/state
status: off
[EMAIL PROTECTED] acpi]# echo "" > /proc/acpi/fan/C31B/state
[EMAIL PROTECTED] acpi]# cat /proc/acpi/fan/C31B/state
status: on
[EMAIL PROTECTED] acpi]# echo "3" > /proc/acpi/fan/C31B/state
[EMAIL PROTECTED] acpi]# cat /proc/acpi/fan/C31B/state
status: off
[EMAIL PROTECTED] acpi]# echo "xxxxx" > /proc/acpi/fan/C31B/state
[EMAIL PROTECTED] acpi]# cat /proc/acpi/fan/C31B/state
status: on
[EMAIL PROTECTED] acpi]# echo "3" > /proc/acpi/fan/C31B/state
[EMAIL PROTECTED] acpi]# cat /proc/acpi/fan/C31B/state
status: off
[EMAIL PROTECTED] acpi]# echo "3x" > /proc/acpi/fan/C31B/state
[EMAIL PROTECTED] acpi]# cat /proc/acpi/fan/C31B/state
status: off
[EMAIL PROTECTED] acpi]# echo "-1x" > /proc/acpi/fan/C31B/state
[EMAIL PROTECTED] acpi]# cat /proc/acpi/fan/C31B/state
status: on
[EMAIL PROTECTED] acpi]#
After applying this patch, the test result is:
[EMAIL PROTECTED] ~]# cat /proc/acpi/fan/C31B/state
status: off
[EMAIL PROTECTED] ~]# echo "" > /proc/acpi/fan/C31B/state
-bash: echo: write error: Invalid argument
[EMAIL PROTECTED] ~]# cat /proc/acpi/fan/C31B/state
status: off
[EMAIL PROTECTED] ~]# echo "3" > /proc/acpi/fan/C31B/state
[EMAIL PROTECTED] ~]# cat /proc/acpi/fan/C31B/state
status: off
[EMAIL PROTECTED] ~]# echo "xxxxx" > /proc/acpi/fan/C31B/state
-bash: echo: write error: Invalid argument
[EMAIL PROTECTED] ~]# cat /proc/acpi/fan/C31B/state
status: off
[EMAIL PROTECTED] ~]# echo "-1x" > /proc/acpi/fan/C31B/state
-bash: echo: write error: Invalid argument
[EMAIL PROTECTED] ~]# cat /proc/acpi/fan/C31B/state
status: off
[EMAIL PROTECTED] ~]# echo "0" > //proc/acpi/fan/C31B/state
[EMAIL PROTECTED] ~]# cat /proc/acpi/fan/C31B/state
status: on
[EMAIL PROTECTED] ~]# echo "4" > //proc/acpi/fan/C31B/state
-bash: echo: write error: Invalid argument
[EMAIL PROTECTED] ~]# cat /proc/acpi/fan/C31B/state
status: on
[EMAIL PROTECTED] ~]# echo "3" > //proc/acpi/fan/C31B/state
[EMAIL PROTECTED] ~]# cat /proc/acpi/fan/C31B/state
status: off
[EMAIL PROTECTED] ~]# echo "0" > //proc/acpi/fan/C31B/state
[EMAIL PROTECTED] ~]# cat /proc/acpi/fan/C31B/state
status: on
[EMAIL PROTECTED] ~]# echo "3x" > //proc/acpi/fan/C31B/state
-bash: echo: write error: Invalid argument
[EMAIL PROTECTED] ~]#
Signed-off-by: Yi Yang <[EMAIL PROTECTED]>
---
fan.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/fan.c b/drivers/acpi/fan.c
index a5a5532..53f7c72 100644
--- a/drivers/acpi/fan.c
+++ b/drivers/acpi/fan.c
@@ -98,7 +98,7 @@ acpi_fan_write_state(struct file *file, const char __user *
buffer,
int result = 0;
struct seq_file *m = file->private_data;
struct acpi_device *device = m->private;
- char state_string[12] = { '\0' };
+ char state_string[3] = { '\0' };
if (count > sizeof(state_string) - 1)
return -EINVAL;
@@ -107,6 +107,12 @@ acpi_fan_write_state(struct file *file, const char __user
* buffer,
return -EFAULT;
state_string[count] = '\0';
+ if ((state_string[0] < '0') || (state_string[0] > '3'))
+ return -EINVAL;
+ if (state_string[1] == '\n')
+ state_string[1] = '\0';
+ if (state_string[1] != '\0')
+ return -EINVAL;
result = acpi_bus_set_power(device->handle,
simple_strtoul(state_string, NULL, 0));
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
