5.4-stable review patch. If anyone has any objections, please let me know.
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From: Tzung-Bi Shih tzungbi@kernel.org
commit e08969c4d65ac31297fcb4d31d4808c789152f68 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/input/keyboard/cros_ec_keyb.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/drivers/input/keyboard/cros_ec_keyb.c +++ b/drivers/input/keyboard/cros_ec_keyb.c @@ -244,6 +244,12 @@ static int cros_ec_keyb_work(struct noti 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");