[PATCH] thermal/drivers/qcom-spmi-temp-alarm: Fix temp_map indexing

[djakov]

From: Georgi Djakov <djakov@xxxxxxxxxx>

Fix the following issue noticed when booting on the db845c-dragonboard:

BUG: KASAN: global-out-of-bounds in qpnp_tm_sync_thresholds+0x11c/0x180 [qcom_spmi_temp_alarm]
Read of size 24 at addr ffffdd2495f01200 by task (udev-worker)/371

CPU: 3 UID: 0 PID: 371 Comm: (udev-worker) Not tainted 7.3.0-rc3 #116 PREEMPT
Hardware name: Thundercomm Dragonboard 845c (DT)
Call trace:
 show_stack+0x18/0x24 (C)
 dump_stack_lvl+0xa4/0xf4
 print_report+0x1f4/0x5ac
 kasan_report+0x84/0xcc
 kasan_check_range+0xf0/0x1a4
 memcpy+0x3c/0xa4
 qpnp_tm_sync_thresholds+0x11c/0x180 [qcom_spmi_temp_alarm]
 qpnp_tm_probe+0x3dc/0xae8 [qcom_spmi_temp_alarm]
 platform_probe+0xc4/0x18c
 really_probe+0x17c/0x4fc
 ...

The buggy address belongs to the variable:
 temp_map_gen1+0x60/0xc4 [qcom_spmi_temp_alarm]

It looks like temp_map is a pointer to the complete temperature map.
Indexing it directly advances the entire map, rather than selecting a
threshold row.

Fix this by dereferencing the temp_map before indexing it to select the
requested threshold row.

Fixes: 703f13285a6c ("thermal/drivers/qcom-spmi-temp-alarm: Add temp alarm data struct based on HW subtype")
Fixes: 1f835c6a4c84 ("thermal/drivers/qcom-spmi-temp-alarm: Prepare to support additional Temp Alarm subtypes")
Signed-off-by: Georgi Djakov <djakov@xxxxxxxxxx>
---
 drivers/thermal/qcom/qcom-spmi-temp-alarm.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/thermal/qcom/qcom-spmi-temp-alarm.c b/drivers/thermal/qcom/qcom-spmi-temp-alarm.c
index fb003ca96454..911ebfd0cdeb 100644
--- a/drivers/thermal/qcom/qcom-spmi-temp-alarm.c
+++ b/drivers/thermal/qcom/qcom-spmi-temp-alarm.c
@@ -345,8 +345,8 @@ static int qpnp_tm_update_critical_trip_temp(struct qpnp_tm_chip *chip,
 	}
 
 skip:
-	memcpy(chip->temp_thresh_map, chip->data->temp_map[threshold],
-		sizeof(chip->temp_thresh_map));
+	memcpy(chip->temp_thresh_map, (*chip->data->temp_map)[threshold],
+	       sizeof(chip->temp_thresh_map));
 	reg |= threshold;
 	if (disable_stage2_shutdown && !chip->require_stage2_shutdown)
 		reg |= SHUTDOWN_CTRL1_OVERRIDE_STAGE2;
@@ -535,8 +535,8 @@ static int qpnp_tm_sync_thresholds(struct qpnp_tm_chip *chip)
 		return ret;
 
 	threshold = reg & SHUTDOWN_CTRL1_THRESHOLD_MASK;
-	memcpy(chip->temp_thresh_map, chip->data->temp_map[threshold],
-		sizeof(chip->temp_thresh_map));
+	memcpy(chip->temp_thresh_map, (*chip->data->temp_map)[threshold],
+	       sizeof(chip->temp_thresh_map));
 
 	return ret;
 }