Linux Kernel Vidtv Driver Pass-By-Value Structs Memory Sanitizer Warning Vulnerability

A vulnerability exists in the Linux kernel's Vidtv driver, where certain functions handle argument structures by value instead of by reference. This issue causes the Memory Sanitizer (MSAN) to issue warnings about uninitialized values. Although only one function has so far triggered a warning, all affected functions share the same problem. The vulnerability arises because the functions do not properly manage the struct data, leading to potential misuse of uninitialized information. The issue can be exploited in scenarios where these functions are called with specific arguments that trigger the MSAN warnings.

Impact

The vulnerability can lead to Memory Sanitizer warnings about uninitialized values, which may indicate a deeper issue with how data is managed and could potentially be exploited in certain conditions.

Reproduction

The vulnerability can be reproduced by calling the 'vidtv_ts_null_write_into' or 'vidtv_ts_pcr_write_into' functions with argument structures that have not been properly initialized. This can be done within the Linux kernel's Vidtv driver context, where these functions are used to write null packets or PCR (Program Clock Reference) packets into a buffer. The Memory Sanitizer will then report warnings about the uninitialized values, highlighting the vulnerability.

Remediation

The vulnerability has been addressed by modifying the affected functions to accept argument structures as constant pointers, rather than by value. This change prevents the uninitialized value warnings from the Memory Sanitizer. Users can apply the latest patches available in the Linux kernel stable tree to mitigate this issue.