[PATCH 4.19 124/125] HID: hiddev: Fix slab-out-of-bounds write in hiddev_ioctl_usage()
From: Greg Kroah-Hartman
Date: Tue Sep 01 2020 - 12:50:27 EST
From: Peilin Ye <yepeilin.cs@xxxxxxxxx>
commit 25a097f5204675550afb879ee18238ca917cba7a upstream.
`uref->usage_index` is not always being properly checked, causing
hiddev_ioctl_usage() to go out of bounds under some cases. Fix it.
Reported-by: syzbot+34ee1b45d88571c2fa8b@xxxxxxxxxxxxxxxxxxxxxxxxx
Link: https://syzkaller.appspot.com/bug?id=f2aebe90b8c56806b050a20b36f51ed6acabe802
Reviewed-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Peilin Ye <yepeilin.cs@xxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/hid/usbhid/hiddev.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/drivers/hid/usbhid/hiddev.c
+++ b/drivers/hid/usbhid/hiddev.c
@@ -532,12 +532,16 @@ static noinline int hiddev_ioctl_usage(s
switch (cmd) {
case HIDIOCGUSAGE:
+ if (uref->usage_index >= field->report_count)
+ goto inval;
uref->value = field->value[uref->usage_index];
if (copy_to_user(user_arg, uref, sizeof(*uref)))
goto fault;
goto goodreturn;
case HIDIOCSUSAGE:
+ if (uref->usage_index >= field->report_count)
+ goto inval;
field->value[uref->usage_index] = uref->value;
goto goodreturn;