CVE-2021-47475

Commit e1f13c879a7c ("staging: comedi: check validity of wMaxPacketSize of usb endpoints found") inadvertently fixed NULL-pointer dereferences when accessing the transfer buffers in case a malicious device has a zero wMaxPacketSize.

Make sure to allocate buffers large enough to handle also the other accesses that are done without a size check (e.g. byte 18 in vmk80xxcntinsnread() for the VMK8061MODEL) to avoid writing beyond the buffers, for example, when doing descriptor fuzzing.

The original driver was for a low-speed device with 8-byte buffers. Support was later added for a device that uses bulk transfers and is presumably a full-speed device with a maximum 64-byte wMaxPacketSize.

References

Affected packages

Git /

Affected ranges

Database specific

unresolved_ranges

[
    {
        "events": [
            {
                "introduced": "2.6.31"
            },
            {
                "fixed": "4.4.292"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "4.5"
            },
            {
                "fixed": "4.9.290"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "4.10"
            },
            {
                "fixed": "4.14.255"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "4.15"
            },
            {
                "fixed": "4.19.217"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "4.20"
            },
            {
                "fixed": "5.4.159"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "5.5"
            },
            {
                "fixed": "5.10.79"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "5.11"
            },
            {
                "fixed": "5.14.18"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "5.15"
            },
            {
                "fixed": "5.15.2"
            }
        ]
    }
]

source

"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-47475.json"