Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752932AbbKHRib (ORCPT ); Sun, 8 Nov 2015 12:38:31 -0500 Received: from mail-wm0-f41.google.com ([74.125.82.41]:36439 "EHLO mail-wm0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752703AbbKHRi1 (ORCPT ); Sun, 8 Nov 2015 12:38:27 -0500 From: Elias Vanderstuyft To: Dmitry Torokhov Cc: linux-input@vger.kernel.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, David Herrmann , Benjamin Tissoires , Elias Vanderstuyft Subject: [PATCH v2 2/2] Input: uinput: Sanity check on ff_effects_max and EV_FF Date: Sun, 8 Nov 2015 18:37:34 +0100 Message-Id: <1447004254-12431-1-git-send-email-elias.vds@gmail.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1442510988-3164-3-git-send-email-elias.vds@gmail.com> References: <1442510988-3164-3-git-send-email-elias.vds@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1889 Lines: 52 Currently the user can set ff_effects_max to zero with the EV_FF bit (and the FF_GAIN and/or FF_AUTOCENTER bits) set, in this case the uninitialized methods ff->set_gain and/or ff->set_autocenter can be dereferenced, resulting in a kernel oops. Check in uinput_create_device() and print a helpful message and return -EINVAL in case the check fails. Signed-off-by: Elias Vanderstuyft --- Changes in v2: - Rebase on pending patches from David Herrmann and Benjamin Tissoires: - v3 Input: uinput - add new UINPUT_DEV_SETUP and UI_ABS_SETUP ioctl - Input: uinput - rework ABS validation - Don't require EV_FF bit to be set when ff_effects_max is non-zero - Move check from uinput_setup_device() to uinput_create_device() - Update commit description At the same time, the new UINPUT_DEV_SETUP and UI_ABS_SETUP ioctls were tested as well (in both orders). The legacy write() (instead of UINPUT_DEV_SETUP) was also tested. drivers/input/misc/uinput.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c index 1d93037..b9d0713 100644 --- a/drivers/input/misc/uinput.c +++ b/drivers/input/misc/uinput.c @@ -272,6 +272,13 @@ static int uinput_create_device(struct uinput_device *udev) input_set_events_per_packet(dev, 60); } + if (test_bit(EV_FF, dev->evbit) && !udev->ff_effects_max) { + printk(KERN_DEBUG "%s: ff_effects_max should be non-zero when FF_BIT is set\n", + UINPUT_NAME); + error = -EINVAL; + goto fail1; + } + if (udev->ff_effects_max) { error = input_ff_create(dev, udev->ff_effects_max); if (error) -- 1.9.3 -- 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/