From: Tzung-Bi Shih Date: Tue, 4 Nov 2025 07:03:10 +0000 (+0000) Subject: Input: cros_ec_keyb - fix an invalid memory access X-Git-Tag: v6.18-rc7~8^2~2 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=e08969c4d65ac31297fcb4d31d4808c789152f68;p=thirdparty%2Flinux.git 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 --- 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");