From: Dinghao Liu Date: Mon, 25 Sep 2023 08:08:44 +0000 (+0800) Subject: ACPI: video: Fix NULL pointer dereference in acpi_video_bus_add() X-Git-Tag: v6.6.17~3832^2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f4dcf06bc6e0161920b700ba3966411d716a321b;p=platform%2Fkernel%2Flinux-rpi.git ACPI: video: Fix NULL pointer dereference in acpi_video_bus_add() acpi_video_bus_add_notify_handler() could free video->input and set it to NULL on failure, but this failure would be missed in its caller acpi_video_bus_add(). As a result, when an error happens in acpi_dev_install_notify_handler(), acpi_video_bus_add() would call acpi_video_bus_remove_notify_handler(), where a potential NULL pointer video->input is dereferenced in input_unregister_device(). Fix this by adding a return value check and adjusting the following error handling code. Fixes: 6f7016819766 ("ACPI: video: Install Notify() handler directly") Signed-off-by: Dinghao Liu [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki --- diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c index 948e31f..b411948 100644 --- a/drivers/acpi/acpi_video.c +++ b/drivers/acpi/acpi_video.c @@ -2057,7 +2057,9 @@ static int acpi_video_bus_add(struct acpi_device *device) !auto_detect) acpi_video_bus_register_backlight(video); - acpi_video_bus_add_notify_handler(video); + error = acpi_video_bus_add_notify_handler(video); + if (error) + goto err_del; error = acpi_dev_install_notify_handler(device, ACPI_DEVICE_NOTIFY, acpi_video_bus_notify); @@ -2067,10 +2069,11 @@ static int acpi_video_bus_add(struct acpi_device *device) return 0; err_remove: + acpi_video_bus_remove_notify_handler(video); +err_del: mutex_lock(&video_list_lock); list_del(&video->entry); mutex_unlock(&video_list_lock); - acpi_video_bus_remove_notify_handler(video); acpi_video_bus_unregister_backlight(video); err_put_video: acpi_video_bus_put_devices(video);