[v2] HID: hid-input: clear unmapped usages
diff mbox series

Message ID 20191207210518.GA181006@dtor-ws
State Mainlined
Commit 4f3882177240a1f55e45a3d241d3121341bead78
Delegated to: Jiri Kosina
Headers show
Series
  • [v2] HID: hid-input: clear unmapped usages
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Commit Message

Dmitry Torokhov Dec. 7, 2019, 9:05 p.m. UTC
We should not be leaving half-mapped usages with potentially invalid
keycodes, as that may confuse hidinput_find_key() when the key is located
by index, which may end up feeding way too large keycode into the VT
keyboard handler and cause OOB write there:

BUG: KASAN: global-out-of-bounds in clear_bit include/asm-generic/bitops-instrumented.h:56 [inline]
BUG: KASAN: global-out-of-bounds in kbd_keycode drivers/tty/vt/keyboard.c:1411 [inline]
BUG: KASAN: global-out-of-bounds in kbd_event+0xe6b/0x3790 drivers/tty/vt/keyboard.c:1495
Write of size 8 at addr ffffffff89a1b2d8 by task syz-executor108/1722
...
 kbd_keycode drivers/tty/vt/keyboard.c:1411 [inline]
 kbd_event+0xe6b/0x3790 drivers/tty/vt/keyboard.c:1495
 input_to_handler+0x3b6/0x4c0 drivers/input/input.c:118
 input_pass_values.part.0+0x2e3/0x720 drivers/input/input.c:145
 input_pass_values drivers/input/input.c:949 [inline]
 input_set_keycode+0x290/0x320 drivers/input/input.c:954
 evdev_handle_set_keycode_v2+0xc4/0x120 drivers/input/evdev.c:882
 evdev_do_ioctl drivers/input/evdev.c:1150 [inline]

Reported-by: syzbot+19340dff067c2d3835c0@syzkaller.appspotmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---

v2: fixed up interaction with hid-multitouch according to Benjamin's
feedback

Please consider tagging for stable.

 drivers/hid/hid-input.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

Comments

Jiri Kosina Dec. 13, 2019, 9:28 a.m. UTC | #1
On Sat, 7 Dec 2019, Dmitry Torokhov wrote:

> We should not be leaving half-mapped usages with potentially invalid
> keycodes, as that may confuse hidinput_find_key() when the key is located
> by index, which may end up feeding way too large keycode into the VT
> keyboard handler and cause OOB write there:
> 
> BUG: KASAN: global-out-of-bounds in clear_bit include/asm-generic/bitops-instrumented.h:56 [inline]
> BUG: KASAN: global-out-of-bounds in kbd_keycode drivers/tty/vt/keyboard.c:1411 [inline]
> BUG: KASAN: global-out-of-bounds in kbd_event+0xe6b/0x3790 drivers/tty/vt/keyboard.c:1495
> Write of size 8 at addr ffffffff89a1b2d8 by task syz-executor108/1722
> ...
>  kbd_keycode drivers/tty/vt/keyboard.c:1411 [inline]
>  kbd_event+0xe6b/0x3790 drivers/tty/vt/keyboard.c:1495
>  input_to_handler+0x3b6/0x4c0 drivers/input/input.c:118
>  input_pass_values.part.0+0x2e3/0x720 drivers/input/input.c:145
>  input_pass_values drivers/input/input.c:949 [inline]
>  input_set_keycode+0x290/0x320 drivers/input/input.c:954
>  evdev_handle_set_keycode_v2+0xc4/0x120 drivers/input/evdev.c:882
>  evdev_do_ioctl drivers/input/evdev.c:1150 [inline]
> 
> Reported-by: syzbot+19340dff067c2d3835c0@syzkaller.appspotmail.com
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> ---
> 
> v2: fixed up interaction with hid-multitouch according to Benjamin's
> feedback
> 
> Please consider tagging for stable.

I'd like to push this for 5.5 (and tag for stable), but would prefer this 
to have gone through the full battery of Benjamin's testing infrastructure 
first.

Benjamin, did you have chance to run Dmitry's patch through your 
machinery?

Thanks,
Benjamin Tissoires Dec. 13, 2019, 11:22 a.m. UTC | #2
Hi,

On Fri, Dec 13, 2019 at 10:28 AM Jiri Kosina <jikos@kernel.org> wrote:
>
> On Sat, 7 Dec 2019, Dmitry Torokhov wrote:
>
> > We should not be leaving half-mapped usages with potentially invalid
> > keycodes, as that may confuse hidinput_find_key() when the key is located
> > by index, which may end up feeding way too large keycode into the VT
> > keyboard handler and cause OOB write there:
> >
> > BUG: KASAN: global-out-of-bounds in clear_bit include/asm-generic/bitops-instrumented.h:56 [inline]
> > BUG: KASAN: global-out-of-bounds in kbd_keycode drivers/tty/vt/keyboard.c:1411 [inline]
> > BUG: KASAN: global-out-of-bounds in kbd_event+0xe6b/0x3790 drivers/tty/vt/keyboard.c:1495
> > Write of size 8 at addr ffffffff89a1b2d8 by task syz-executor108/1722
> > ...
> >  kbd_keycode drivers/tty/vt/keyboard.c:1411 [inline]
> >  kbd_event+0xe6b/0x3790 drivers/tty/vt/keyboard.c:1495
> >  input_to_handler+0x3b6/0x4c0 drivers/input/input.c:118
> >  input_pass_values.part.0+0x2e3/0x720 drivers/input/input.c:145
> >  input_pass_values drivers/input/input.c:949 [inline]
> >  input_set_keycode+0x290/0x320 drivers/input/input.c:954
> >  evdev_handle_set_keycode_v2+0xc4/0x120 drivers/input/evdev.c:882
> >  evdev_do_ioctl drivers/input/evdev.c:1150 [inline]
> >
> > Reported-by: syzbot+19340dff067c2d3835c0@syzkaller.appspotmail.com
> > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> > ---
> >
> > v2: fixed up interaction with hid-multitouch according to Benjamin's
> > feedback
> >
> > Please consider tagging for stable.
>
> I'd like to push this for 5.5 (and tag for stable), but would prefer this
> to have gone through the full battery of Benjamin's testing infrastructure
> first.
>
> Benjamin, did you have chance to run Dmitry's patch through your
> machinery?

yep, this one was OK, so:
Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

Cheers,
Benjamin

>
> Thanks,
>
> --
> Jiri Kosina
> SUSE Labs
>
Jiri Kosina Dec. 13, 2019, 8:42 p.m. UTC | #3
On Fri, 13 Dec 2019, Benjamin Tissoires wrote:

> > > We should not be leaving half-mapped usages with potentially invalid
> > > keycodes, as that may confuse hidinput_find_key() when the key is located
> > > by index, which may end up feeding way too large keycode into the VT
> > > keyboard handler and cause OOB write there:
> > >
> > > BUG: KASAN: global-out-of-bounds in clear_bit include/asm-generic/bitops-instrumented.h:56 [inline]
> > > BUG: KASAN: global-out-of-bounds in kbd_keycode drivers/tty/vt/keyboard.c:1411 [inline]
> > > BUG: KASAN: global-out-of-bounds in kbd_event+0xe6b/0x3790 drivers/tty/vt/keyboard.c:1495
> > > Write of size 8 at addr ffffffff89a1b2d8 by task syz-executor108/1722
> > > ...
> > >  kbd_keycode drivers/tty/vt/keyboard.c:1411 [inline]
> > >  kbd_event+0xe6b/0x3790 drivers/tty/vt/keyboard.c:1495
> > >  input_to_handler+0x3b6/0x4c0 drivers/input/input.c:118
> > >  input_pass_values.part.0+0x2e3/0x720 drivers/input/input.c:145
> > >  input_pass_values drivers/input/input.c:949 [inline]
> > >  input_set_keycode+0x290/0x320 drivers/input/input.c:954
> > >  evdev_handle_set_keycode_v2+0xc4/0x120 drivers/input/evdev.c:882
> > >  evdev_do_ioctl drivers/input/evdev.c:1150 [inline]
> > >
> > > Reported-by: syzbot+19340dff067c2d3835c0@syzkaller.appspotmail.com
> > > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> > > ---
> > >
> > > v2: fixed up interaction with hid-multitouch according to Benjamin's
> > > feedback
> > >
> > > Please consider tagging for stable.
> >
> > I'd like to push this for 5.5 (and tag for stable), but would prefer this
> > to have gone through the full battery of Benjamin's testing infrastructure
> > first.
> >
> > Benjamin, did you have chance to run Dmitry's patch through your
> > machinery?
> 
> yep, this one was OK, so:
> Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

Thanks, I am queuing this in for-5.5/upstream-fixes.

Patch
diff mbox series

diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 63855f275a38..9428f49fd218 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -1132,9 +1132,15 @@  static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel
 	}
 
 mapped:
-	if (device->driver->input_mapped && device->driver->input_mapped(device,
-				hidinput, field, usage, &bit, &max) < 0)
-		goto ignore;
+	if (device->driver->input_mapped &&
+	    device->driver->input_mapped(device, hidinput, field, usage,
+					 &bit, &max) < 0) {
+		/*
+		 * The driver indicated that no further generic handling
+		 * of the usage is desired.
+		 */
+		return;
+	}
 
 	set_bit(usage->type, input->evbit);
 
@@ -1215,9 +1221,11 @@  static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel
 		set_bit(MSC_SCAN, input->mscbit);
 	}
 
-ignore:
 	return;
 
+ignore:
+	usage->type = 0;
+	usage->code = 0;
 }
 
 static void hidinput_handle_scroll(struct hid_usage *usage,