[PATCH 6.6.y] platform/x86: ISST: Validate max level for set feature

[Sasha Levin <sashal@kernel.org>]

From: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

[ Upstream commit e45d6b8472861d3bac86bb37f8556a7c5aca3266 ]

Validate the level before setting, so that it fails early instead of
failing later when checking the bit mask for allowed levels.

Fixes: ea009e4769fa3 ("platform/x86: ISST: Add SST-PP support via TPMI")
Cc: stable@vger.kernel.org
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://patch.msgid.link/20260811221514.3905817-3-srinivas.pandruvada@linux.intel.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
[ Adjusted context for the missing write_blocked/CAP_SYS_ADMIN permission check. ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c b/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c
index df0b0118b751f..246013b26c953 100644
--- a/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c
+++ b/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c
@@ -747,6 +747,9 @@ static int isst_if_set_perf_level(void __user *argp)
 	if (!power_domain_info)
 		return -EINVAL;
 
+	if (perf_level.level > power_domain_info->max_level)
+		return -EINVAL;
+
 	if (!(power_domain_info->pp_header.allowed_level_mask & BIT(perf_level.level)))
 		return -EINVAL;
 
-- 
2.53.0