Introduction:

A recently resolved vulnerability (CVE-2024-56705) in the Linux kernel occurs within the media driver subsystem, specifically the AtomISP driver. This vulnerability could lead to potential issues if not addressed properly. In this post, we will discuss the details of the vulnerability, the code snippet that resolves the issue, and provide some links to original references.

Details

The issue resides in the ia_css_3a_statistics_allocate() function of the Linux kernel. The function does not check the result of the allocation process for the rgby_data memory. If rgby_data is not successfully allocated, it may trigger the assertion (host_stats->rgby_data) in the function ia_css_s3a_hmem_decode().

To fix this potential issue, a check has been added to ensure that the rgby_data memory allocation is successful before it's passed to the ia_css_s3a_hmem_decode() function.

The code snippet that addresses the issue is shown below

struct ia_css_3a_statistics *ia_css_3a_statistics_allocate(unsigned int size)
{
    ...
    host_stats->rgby_data = ia_css_cpu_mem_alloc(size * IA_CSS_STATISTICS_U_SHIFT_RUBY_VAL_WIDTH);
    + if (!host_stats->rgby_data) {
    +     ia_css_cpu_mem_free((void *)host_stats->data);
    +     ia_css_cpu_mem_free(host_stats);
    +     return NULL;
    + }
    ...
}

The added code checks whether the host_stats->rgby_data is NULL after the ia_css_cpu_mem_alloc() function call. If it is NULL, it means that the memory allocation has failed, and the function will deallocate the previously allocated memory and return NULL instead of triggering the assertion in ia_css_s3a_hmem_decode().

- Linux Kernel Git Commit
- Patch Announcement Mailing List

Exploit details

Currently, there is no known exploit targeting this vulnerability as it has been addressed before becoming part of the main release. Users, especially those using the affected media AtomISP driver, should update their systems regularly to avoid being affected by vulnerabilities like this one.

Conclusion

The Linux kernel vulnerability CVE-2024-56705 has been successfully resolved, preventing potential issues arising from memory allocation failure in AtomISP driver. Ensuring proper checks on memory allocation process can help enhance system security and maintain driver stability. Keep your Linux kernel up-to-date to avoid running into potential vulnerabilities.

Timeline

Published on: 12/28/2024 10:15:19 UTC
Last modified on: 01/20/2025 06:26:33 UTC