From 2a96243e22f880ad53a977e09680aee276dc50b5 Mon Sep 17 00:00:00 2001 From: Zhang Rui Date: Wed, 8 Mar 2023 11:07:11 +0800 Subject: thermal: intel: x86_pkg_temp_thermal: Add lower bound check for sysfs input When setting a trip point temperature from sysfs, there is an upper bound check on the user input, but no lower bound check. As hardware register has 7 bits for a trip point temperature, the offset to tj_max of the input temperature must be equal to/less than 0x7f. Or else, 1. bogus temperature is updated into the trip temperature bits. 2. the upper bits of the register can be polluted. For example, $ rdmsr 0x1b2 2000003 $ echo -180000 > /sys/class/thermal/thermal_zone1/trip_point_1_temp $ rdmsr 0x1b2 3980003 Not only the trip point temp is set to 76C on this platform (tj_max is 100), the Power Notification (Bit 24) is also enabled erronously. Fix the problem by adding lower bound check for sysfs input. Reported-by: Dan Carpenter Link: https://lore.kernel.org/all/add7a378-4d50-4ba1-81d3-a0c17db25a0b@kili.mountain/ Signed-off-by: Zhang Rui Signed-off-by: Rafael J. Wysocki --- drivers/thermal/intel/x86_pkg_temp_thermal.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'drivers/thermal/intel') diff --git a/drivers/thermal/intel/x86_pkg_temp_thermal.c b/drivers/thermal/intel/x86_pkg_temp_thermal.c index 1c2de84742df..128ee02596ed 100644 --- a/drivers/thermal/intel/x86_pkg_temp_thermal.c +++ b/drivers/thermal/intel/x86_pkg_temp_thermal.c @@ -124,14 +124,16 @@ sys_set_trip_temp(struct thermal_zone_device *tzd, int trip, int temp) { struct zone_device *zonedev = tzd->devdata; u32 l, h, mask, shift, intr; - int tj_max, ret; + int tj_max, val, ret; tj_max = intel_tcc_get_tjmax(zonedev->cpu); if (tj_max < 0) return tj_max; tj_max *= 1000; - if (trip >= MAX_NUMBER_OF_TRIPS || temp >= tj_max) + val = (tj_max - temp)/1000; + + if (trip >= MAX_NUMBER_OF_TRIPS || val < 0 || val > 0x7f) return -EINVAL; ret = rdmsr_on_cpu(zonedev->cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, @@ -156,7 +158,7 @@ sys_set_trip_temp(struct thermal_zone_device *tzd, int trip, int temp) if (!temp) { l &= ~intr; } else { - l |= (tj_max - temp)/1000 << shift; + l |= val << shift; l |= intr; } -- cgit v1.2.3