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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2019-12-07 13:05:18 -0800
committerJiri Kosina <jkosina@suse.cz>2019-12-13 13:43:15 +0100
commit4f3882177240a1f55e45a3d241d3121341bead78 (patch)
tree5be71989bd3da66fe7946030f96678e0e20df15f
parentfd0913768701612fc2b8ab9c8a5c019133e8d978 (diff)
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HID: hid-input: clear unmapped usages
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] Cc: stable@vger.kernel.org Reported-by: syzbot+19340dff067c2d3835c0@syzkaller.appspotmail.com Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
-rw-r--r--drivers/hid/hid-input.c16
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 63855f275a38..dea9cc65bf80 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 @@ mapped:
set_bit(MSC_SCAN, input->mscbit);
}
-ignore:
return;
+ignore:
+ usage->type = 0;
+ usage->code = 0;
}
static void hidinput_handle_scroll(struct hid_usage *usage,