[PATCH 5.10, 5.15, 6.1] hwmon: (drivetemp) Fix driver producing garbage data when SCSI errors occur

[Nobuhiro Iwamatsu]

From: Daniil Stas <daniil.stas@xxxxxxxxxx>

commit 82163d63ae7a4c36142cd252388737205bb7e4b9 upstream.

scsi_execute_cmd() function can return both negative (linux codes) and
positive (scsi_cmnd result field) error codes.

Currently the driver just passes error codes of scsi_execute_cmd() to
hwmon core, which is incorrect because hwmon only checks for negative
error codes. This leads to hwmon reporting uninitialized data to
userspace in case of SCSI errors (for example if the disk drive was
disconnected).

This patch checks scsi_execute_cmd() output and returns -EIO if it's
error code is positive.

Fixes: 5b46903d8bf37 ("hwmon: Driver for disk and solid state drives with temperature sensors")
Signed-off-by: Daniil Stas <daniil.stas@xxxxxxxxxx>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: Chris Healy <cphealy@xxxxxxxxx>
Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Cc: Bart Van Assche <bvanassche@xxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-scsi@xxxxxxxxxxxxxxx
Cc: linux-ide@xxxxxxxxxxxxxxx
Cc: linux-hwmon@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20250105213618.531691-1-daniil.stas@xxxxxxxxxx
[groeck: Avoid inline variable declaration for portability]
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Nobuhiro Iwamatsu (CIP) <nobuhiro.iwamatsu.x90@mail.toshiba>
---
 drivers/hwmon/drivetemp.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/hwmon/drivetemp.c b/drivers/hwmon/drivetemp.c
index 5bac2b0fc7bb6a..b3de637a3a1f29 100644
--- a/drivers/hwmon/drivetemp.c
+++ b/drivers/hwmon/drivetemp.c
@@ -165,6 +165,7 @@ static int drivetemp_scsi_command(struct drivetemp_data *st,
 {
 	u8 scsi_cmd[MAX_COMMAND_SIZE];
 	int data_dir;
+	int err;
 
 	memset(scsi_cmd, 0, sizeof(scsi_cmd));
 	scsi_cmd[0] = ATA_16;
@@ -192,9 +193,12 @@ static int drivetemp_scsi_command(struct drivetemp_data *st,
 	scsi_cmd[12] = lba_high;
 	scsi_cmd[14] = ata_command;
 
-	return scsi_execute_req(st->sdev, scsi_cmd, data_dir,
-				st->smartdata, ATA_SECT_SIZE, NULL, HZ, 5,
-				NULL);
+	err = scsi_execute_req(st->sdev, scsi_cmd, data_dir,
+			       st->smartdata, ATA_SECT_SIZE, NULL, HZ, 5,
+			       NULL);
+	if (err > 0)
+		err = -EIO;
+	return err;
 }
 
 static int drivetemp_ata_command(struct drivetemp_data *st, u8 feature,
-- 
2.55.0