Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752948AbaBEAzA (ORCPT ); Tue, 4 Feb 2014 19:55:00 -0500 Received: from g4t0017.houston.hp.com ([15.201.24.20]:12392 "EHLO g4t0017.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751470AbaBEAy6 (ORCPT ); Tue, 4 Feb 2014 19:54:58 -0500 From: Toshi Kani To: rjw@rjwysocki.net Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, Toshi Kani Subject: [PATCH] ACPI hotplug: Fix panic on eject to ejected device Date: Tue, 4 Feb 2014 17:48:28 -0700 Message-Id: <1391561308-18893-1-git-send-email-toshi.kani@hp.com> X-Mailer: git-send-email 1.8.3.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When an eject request is sent to an ejected ACPI device, the following panic occurs: ACPI: \_SB_.SCK3.CPU3: ACPI_NOTIFY_EJECT_REQUEST event BUG: unable to handle kernel NULL pointer dereference at 0000000000000070 IP: [] acpi_device_hotplug+0x10b/0x33b : Call Trace: [] acpi_hotplug_work_fn+0x1c/0x27 [] process_one_work+0x175/0x430 [] worker_thread+0x11b/0x3a0 This is becase device->handler is NULL in acpi_device_hotplug(). This case was used to fail in acpi_hotplug_notify_cb() as the target had no acpi_deivce. However, acpi_device now exists after ejection. Added a check to verify if acpi_device->handler is valid for an eject request in acpi_hotplug_notify_cb(). Note that handler passed from an argument is still valid while acpi_device->handler is NULL. Signed-off-by: Toshi Kani --- drivers/acpi/scan.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 7384158..5cf6adf 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -484,7 +484,6 @@ static void acpi_device_hotplug(void *data, u32 src) static void acpi_hotplug_notify_cb(acpi_handle handle, u32 type, void *data) { u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; - struct acpi_scan_handler *handler = data; struct acpi_device *adev; acpi_status status; @@ -500,7 +499,9 @@ static void acpi_hotplug_notify_cb(acpi_handle handle, u32 type, void *data) break; case ACPI_NOTIFY_EJECT_REQUEST: acpi_handle_debug(handle, "ACPI_NOTIFY_EJECT_REQUEST event\n"); - if (!handler->hotplug.enabled) { + if (!adev->handler) + goto err_out; + if (!adev->handler->hotplug.enabled) { acpi_handle_err(handle, "Eject disabled\n"); ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED; goto err_out; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/