CVE-2021-47383

This issue happens when a userspace program does an ioctl FBIOPUT_VSCREENINFO passing the fb_var_screeninfo struct containing only the fields xres, yres, and bits_per_pixel with values.

If this struct is the same as the previous ioctl, the vc_resize() detects it and doesn't call the resize_screen(), leaving the fb_var_screeninfo incomplete. And this leads to the updatescrollmode() calculates a wrong value to fbcon_display->vrows, which makes the real_y() return a wrong value of y, and that value, eventually, causes the imageblit to access an out-of-bound address value.

To solve this issue I made the resize_screen() be called even if the screen does not need any resizing, so it will "fix and fill" the fb_var_screeninfo independently.

References

Affected packages

Git /

Affected ranges

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-47383.json"

unresolved_ranges

[
    {
        "events": [
            {
                "introduced": "0"
            },
            {
                "fixed": "4.4.286"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "4.5"
            },
            {
                "fixed": "4.9.285"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "4.10"
            },
            {
                "fixed": "4.14.249"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "4.15"
            },
            {
                "fixed": "4.19.209"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "4.20"
            },
            {
                "fixed": "5.4.151"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "5.5"
            },
            {
                "fixed": "5.10.71"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "5.11"
            },
            {
                "fixed": "5.14.10"
            }
        ]
    }
]