thermal/int340x_thermal: Prevent page fault on .set_mode() op

Starting from commit "thermal/int340x_thermal: Don't require IDSP to
exist", priv->current_uuid_index is initialized to -1. This value may
be passed to int3400_thermal_run_osc() from int3400_thermal_set_mode,
contributing to page fault when accessing int3400_thermal_uuids array
at index -1.

This commit adds a check on uuid value to int3400_thermal_run_osc.

Fixes: 8d485da0ddee ("thermal/int340x_thermal: Don't require IDSP to exist")
Signed-off-by: Bartosz Szczepanek <bsz@semihalf.com>
Reviewed-by: Pandruvada, Srinivas <srinivas.pandruvada@linux.intel.com>
[ rzhang: Add Fixes tag ]
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20200708134613.131555-1-bsz@semihalf.com

diff --git a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
index 0b3a626..12448cc 100644 (file)
--- a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
+++ b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
@@ -216,11 +216,16 @@ static int int3400_thermal_run_osc(acpi_handle handle,
        acpi_status status;
        int result = 0;
        struct acpi_osc_context context = {
-               .uuid_str = int3400_thermal_uuids[uuid],
+               .uuid_str = NULL,
                .rev = 1,
                .cap.length = 8,
        };
 
+       if (uuid < 0 || uuid >= INT3400_THERMAL_MAXIMUM_UUID)
+               return -EINVAL;
+
+       context.uuid_str = int3400_thermal_uuids[uuid];
+
        buf[OSC_QUERY_DWORD] = 0;
        buf[OSC_SUPPORT_DWORD] = enable;