blob: c77f94dc5836bfe77d611c60396cae28da5f4f54 [file] [log] [blame]
From 248e5c83fd23e41c2aa9f075f27e769c9763f71a Mon Sep 17 00:00:00 2001
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Date: Sat, 7 Dec 2019 13:05:18 -0800
Subject: [PATCH] HID: hid-input: clear unmapped usages
commit 4f3882177240a1f55e45a3d241d3121341bead78 upstream.
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>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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 @@ 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,
--
2.7.4