Input: adp5588-keys Add check on return code

Commit Message

Denis Arefev March 31, 2025, 9:49 a.m. UTC

The adp5588_read() function can return 0 or a negative value.
If the function returns 0 then a buffer overflow  occurs.
kpad->keycode[0 - 1].

If the function returns a negative value, then the array kpad->keycode
is accessed with an incorrectly calculated index.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Denis Arefev <[e-mail]>
---
 drivers/input/keyboard/adp5588-keys.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

Patch

diff --git a/drivers/input/keyboard/adp5588-keys.c b/drivers/input/keyboard/adp5588-keys.c
index dc734974ce06..e329320d4ae3 100644
--- a/drivers/input/keyboard/adp5588-keys.c
+++ b/drivers/input/keyboard/adp5588-keys.c
@@ -519,14 +519,19 @@  static void adp5588_report_events(struct adp5588_kpad *kpad, int ev_cnt)
 	int i;
 
 	for (i = 0; i < ev_cnt; i++) {
-		int key = adp5588_read(kpad->client, KEY_EVENTA + i);
-		int key_val = key & KEY_EV_MASK;
-		int key_press = key & KEY_EV_PRESSED;
+		int key, key_val, key_press;
+
+		key = adp5588_read(kpad->client, KEY_EVENTA + i);
+		if (key < 0)
+			continue;
+
+		key_val = key & KEY_EV_MASK;
+		key_press = key & KEY_EV_PRESSED;
 
 		if (key_val >= GPI_PIN_BASE && key_val <= GPI_PIN_END) {
 			/* gpio line used as IRQ source */
 			adp5588_gpio_irq_handle(kpad, key_val, key_press);
-		} else {
+		} else if (key_val > 0) {
 			int row = (key_val - 1) / ADP5588_COLS_MAX;
 			int col =  (key_val - 1) % ADP5588_COLS_MAX;
 			int code = MATRIX_SCAN_CODE(row, col, kpad->row_shift);