[Linux-kernel-mentees] [PATCH v2] usbhid: Fix slab-out-of-bounds write in hiddev_ioctl_usage()
From: Peilin Ye <hidden>
Date: 2020-07-20 19:53:40
Also in:
linux-kernel-mentees, linux-usb, lkml
Subsystem:
hid core layer, the rest, usb hid/hidbp drivers (usb keyboards, mice, remote controls, ...) · Maintainers:
Jiri Kosina, Benjamin Tissoires, Linus Torvalds
`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@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=f2aebe90b8c56806b050a20b36f51ed6acabe802 Signed-off-by: Peilin Ye <redacted> --- Change in v2: - Add the same check for the `HIDIOCGUSAGE` case. (Suggested by Dan Carpenter [off-list ref]) drivers/hid/usbhid/hiddev.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c
index 4140dea693e9..4f97e6c12059 100644
--- a/drivers/hid/usbhid/hiddev.c
+++ b/drivers/hid/usbhid/hiddev.c@@ -519,12 +519,16 @@ static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, 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;
--
2.25.1