CVE-2021-47383

A vulnerability was found in the Linux kernel's tty subsystem within the imageblit function when a userspace program performs an ioctl operation with the FBIOPUT_VSCREENINFO command, passing a fb_var_screeninfo structure with limited fields. If the structure’s values remain unchanged from a previous ioctl call, the kernel fails to fully update the screen information, leading to incorrect calculations of screen dimensions potentially causing system crashes or instability.

This vulnerability is rated as a moderate severity because it can lead to system crashes by accessing invalid memory addresses, it does not pose a direct threat to data security or allow unauthorized access.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.