diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/thermal/thermal_core.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index 7dc7cb53ce6f..7e669b60a065 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -1192,7 +1192,20 @@ thermal_zone_device_register_with_trips(const char *type, struct thermal_trip *t return ERR_PTR(-EINVAL); } - if (num_trips > THERMAL_MAX_TRIPS || num_trips < 0 || mask >> num_trips) { + /* + * Max trip count can't exceed 31 as the "mask >> num_trips" condition. + * For example, shifting by 32 will result in compiler warning: + * warning: right shift count >= width of type [-Wshift-count- overflow] + * + * Also "mask >> num_trips" will always be true with 32 bit shift. + * E.g. mask = 0x80000000 for trip id 31 to be RW. Then + * mask >> 32 = 0x80000000 + * This will result in failure for the below condition. + * + * Check will be true when the bit 31 of the mask is set. + * 32 bit shift will cause overflow of 4 byte integer. + */ + if (num_trips > (BITS_PER_TYPE(int) - 1) || num_trips < 0 || mask >> num_trips) { pr_err("Incorrect number of thermal trips\n"); return ERR_PTR(-EINVAL); } |