From e08969c4d65ac31297fcb4d31d4808c789152f68 Mon Sep 17 00:00:00 2001 From: Tzung-Bi Shih Date: Tue, 4 Nov 2025 07:03:10 +0000 Subject: [PATCH] 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 Link: https://patch.msgid.link/20251104070310.3212712-1-tzungbi@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov --- drivers/input/keyboard/cros_ec_keyb.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/input/keyboard/cros_ec_keyb.c b/drivers/input/keyboard/cros_ec_keyb.c index c1e53d87c8a75..067f2cd57e04e 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"); -- 2.47.3