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authorTzung-Bi Shih <tzungbi@kernel.org>2025-11-04 07:03:10 +0000
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2025-11-04 16:03:26 -0800
commite08969c4d65ac31297fcb4d31d4808c789152f68 (patch)
tree8d411f09404b850e40d64b68f8eac8e22aeaadfd
parentd83f1512758f4ef6fc5e83219fe7eeeb6b428ea4 (diff)
Input: cros_ec_keyb - fix an invalid memory access
If cros_ec_keyb_register_matrix() isn't called (due to `buttons_switches_only`) in cros_ec_keyb_probe(), `ckdev->idev` remains NULL. An invalid memory access is observed in cros_ec_keyb_process() when receiving an EC_MKBP_EVENT_KEY_MATRIX event in cros_ec_keyb_work() in such case. Unable to handle kernel read from unreadable memory at virtual address 0000000000000028 ... x3 : 0000000000000000 x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: input_event cros_ec_keyb_work blocking_notifier_call_chain ec_irq_thread It's still unknown about why the kernel receives such malformed event, in any cases, the kernel shouldn't access `ckdev->idev` and friends if the driver doesn't intend to initialize them. Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org> Link: https://patch.msgid.link/20251104070310.3212712-1-tzungbi@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
-rw-r--r--drivers/input/keyboard/cros_ec_keyb.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/input/keyboard/cros_ec_keyb.c b/drivers/input/keyboard/cros_ec_keyb.c
index c1e53d87c8a7..067f2cd57e04 100644
--- a/drivers/input/keyboard/cros_ec_keyb.c
+++ b/drivers/input/keyboard/cros_ec_keyb.c
@@ -261,6 +261,12 @@ static int cros_ec_keyb_work(struct notifier_block *nb,
case EC_MKBP_EVENT_KEY_MATRIX:
pm_wakeup_event(ckdev->dev, 0);
+ if (!ckdev->idev) {
+ dev_warn_once(ckdev->dev,
+ "Unexpected key matrix event\n");
+ return NOTIFY_OK;
+ }
+
if (ckdev->ec->event_size != ckdev->cols) {
dev_err(ckdev->dev,
"Discarded incomplete key matrix event.\n");