Vulnerability CVE-2024-41035
Published: 2024-07-29

Description:
In the Linux kernel, the following vulnerability has been resolved:

USB: core: Fix duplicate endpoint bug by clearing reserved bits in the descriptor

Syzbot has identified a bug in usbcore (see the Closes: tag below)
caused by our assumption that the reserved bits in an endpoint
descriptor's bEndpointAddress field will always be 0. As a result of
the bug, the endpoint_is_duplicate() routine in config.c (and possibly
other routines as well) may believe that two descriptors are for
distinct endpoints, even though they have the same direction and
endpoint number. This can lead to confusion, including the bug
identified by syzbot (two descriptors with matching endpoint numbers
and directions, where one was interrupt and the other was bulk).

To fix the bug, we will clear the reserved bits in bEndpointAddress
when we parse the descriptor. (Note that both the USB-2.0 and USB-3.1
specs say these bits are "Reserved, reset to zero".) This requires us
to make a copy of the descriptor earlier in usb_parse_endpoint() and
use the copy instead of the original when checking for duplicates.

 References:
https://git.kernel.org/stable/c/d8418fd083d1b90a6c007cf8dcf81aeae274727b
https://git.kernel.org/stable/c/60abea505b726b38232a0ef410d2bd1994a77f78
https://git.kernel.org/stable/c/d09dd21bb5215d583ca9a1cb1464dbc77a7e88cf
https://git.kernel.org/stable/c/2bd8534a1b83c65702aec3cab164170f8e584188
https://git.kernel.org/stable/c/9edcf317620d7c6a8354911b69b874cf89716646
https://git.kernel.org/stable/c/647d61aef106dbed9c70447bcddbd4968e67ca64
https://git.kernel.org/stable/c/37514a5c1251a8c5c95c323f55050736e7069ac7
https://git.kernel.org/stable/c/a368ecde8a5055b627749b09c6218ef793043e47
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