Re: [PATCH 4.19 124/125] HID: hiddev: Fix slab-out-of-bounds write in hiddev_ioctl_usage()

Pavel Machek
2020-09-01T19:12:17Z

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Hi!

> 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.

Well, the code is quite confusig, but:

a) does HIDIOCGCOLLECTIONINDEX need same checking?

b) should we check this using some kind of _nospec() variant to
prevent speculation attacks?

Best regards,
Pavel
--
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