From 6594d87ebd8371f4b67f7ab4b68f172b139b78d6 Mon Sep 17 00:00:00 2001 From: Yi Yang Date: Sat, 14 Jun 2008 00:52:06 -0400 Subject: [PATCH] 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 Signed-off-by: Andi Kleen Acked-by: Zhang Rui Signed-off-by: Len Brown --- drivers/acpi/fan.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) 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)); -- 2.20.1