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authorYi Yang <yi.y.yang@intel.com>2008-06-14 06:52:06 +0200
committerAndi Kleen <andi@basil.nowhere.org>2008-07-16 23:27:01 +0200
commit6594d87ebd8371f4b67f7ab4b68f172b139b78d6 (patch)
tree324aba7fecae632e08e7b1182e3322423fe6092e
parentACPI: fix checkpatch.pl complaints in scan.c (diff)
downloadlinux-6594d87ebd8371f4b67f7ab4b68f172b139b78d6.tar.xz
linux-6594d87ebd8371f4b67f7ab4b68f172b139b78d6.zip
ACPI: fix acpi fan state set error
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: [root@localhost acpi]# cat /proc/acpi/fan/C31B/state status: off [root@localhost acpi]# echo "" > /proc/acpi/fan/C31B/state [root@localhost acpi]# cat /proc/acpi/fan/C31B/state status: on [root@localhost acpi]# echo "3" > /proc/acpi/fan/C31B/state [root@localhost acpi]# cat /proc/acpi/fan/C31B/state status: off [root@localhost acpi]# echo "xxxxx" > /proc/acpi/fan/C31B/state [root@localhost 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: [root@localhost acpi]# cat /proc/acpi/fan/C31B/state status: off [root@localhost acpi]# echo "" > /proc/acpi/fan/C31B/state [root@localhost acpi]# cat /proc/acpi/fan/C31B/state status: on [root@localhost acpi]# echo "3" > /proc/acpi/fan/C31B/state [root@localhost acpi]# cat /proc/acpi/fan/C31B/state status: off [root@localhost acpi]# echo "xxxxx" > /proc/acpi/fan/C31B/state [root@localhost acpi]# cat /proc/acpi/fan/C31B/state status: on [root@localhost acpi]# echo "3" > /proc/acpi/fan/C31B/state [root@localhost acpi]# cat /proc/acpi/fan/C31B/state status: off [root@localhost acpi]# echo "3x" > /proc/acpi/fan/C31B/state [root@localhost acpi]# cat /proc/acpi/fan/C31B/state status: off [root@localhost acpi]# echo "-1x" > /proc/acpi/fan/C31B/state [root@localhost acpi]# cat /proc/acpi/fan/C31B/state status: on [root@localhost acpi]# After applying this patch, the test result is: [root@localhost ~]# cat /proc/acpi/fan/C31B/state status: off [root@localhost ~]# echo "" > /proc/acpi/fan/C31B/state -bash: echo: write error: Invalid argument [root@localhost ~]# cat /proc/acpi/fan/C31B/state status: off [root@localhost ~]# echo "3" > /proc/acpi/fan/C31B/state [root@localhost ~]# cat /proc/acpi/fan/C31B/state status: off [root@localhost ~]# echo "xxxxx" > /proc/acpi/fan/C31B/state -bash: echo: write error: Invalid argument [root@localhost ~]# cat /proc/acpi/fan/C31B/state status: off [root@localhost ~]# echo "-1x" > /proc/acpi/fan/C31B/state -bash: echo: write error: Invalid argument [root@localhost ~]# cat /proc/acpi/fan/C31B/state status: off [root@localhost ~]# echo "0" > //proc/acpi/fan/C31B/state [root@localhost ~]# cat /proc/acpi/fan/C31B/state status: on [root@localhost ~]# echo "4" > //proc/acpi/fan/C31B/state -bash: echo: write error: Invalid argument [root@localhost ~]# cat /proc/acpi/fan/C31B/state status: on [root@localhost ~]# echo "3" > //proc/acpi/fan/C31B/state [root@localhost ~]# cat /proc/acpi/fan/C31B/state status: off [root@localhost ~]# echo "0" > //proc/acpi/fan/C31B/state [root@localhost ~]# cat /proc/acpi/fan/C31B/state status: on [root@localhost ~]# echo "3x" > //proc/acpi/fan/C31B/state -bash: echo: write error: Invalid argument [root@localhost ~]# Signed-off-by: Yi Yang <yi.y.yang@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
-rw-r--r--drivers/acpi/fan.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/acpi/fan.c b/drivers/acpi/fan.c
index 6cf10cbc1eee..55c17afbe669 100644
--- a/drivers/acpi/fan.c
+++ b/drivers/acpi/fan.c
@@ -148,7 +148,7 @@ 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;
@@ -157,6 +157,12 @@ 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));