[PATCH 1/3] platform/x86: panasonic-laptop: Check minimum SQTY value

[Hans de Goede <hdegoede@redhat.com>]

The panasonic laptop code in various places uses the sinf array with index
values of 0 - SINF_CUR_BRIGHT(0x0d) without checking that the sinf array
is big enough.

Check for a minimum SQTY value of SINF_CUR_BRIGHT to avoid out of bounds
accesses of the sinf array.

Note SQTY returning SINF_CUR_BRIGHT is ok because the driver adds one extra
entry to the sinf array.

Fixes: e424fb8cc4e6 ("panasonic-laptop: avoid overflow in acpi_pcc_hotkey_add()")
Cc: stable@vger.kernel.org
Tested-by: James Harmison <jharmison@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/platform/x86/panasonic-laptop.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/panasonic-laptop.c b/drivers/platform/x86/panasonic-laptop.c
index cf845ee1c7b1..d7f9017a5a13 100644
--- a/drivers/platform/x86/panasonic-laptop.c
+++ b/drivers/platform/x86/panasonic-laptop.c
@@ -963,8 +963,8 @@ static int acpi_pcc_hotkey_add(struct acpi_device *device)
 
 	num_sifr = acpi_pcc_get_sqty(device);
 
-	if (num_sifr < 0 || num_sifr > 255) {
-		pr_err("num_sifr out of range");
+	if (num_sifr < SINF_CUR_BRIGHT || num_sifr > 255) {
+		pr_err("num_sifr %d out of range %d - 255\n", num_sifr, SINF_CUR_BRIGHT);
 		return -ENODEV;
 	}
 
-- 
2.46.0