Messages in this thread Patch in this message | | | From | 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 |
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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 <elias.vds@gmail.com> --- 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
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