CVE-2022-48739 in Linux
Summary
by MITRE • 06/20/2024
In the Linux kernel, the following vulnerability has been resolved:
ASoC: hdmi-codec: Fix OOB memory accesses
Correct size of iec_status array by changing it to the size of status array of the struct snd_aes_iec958. This fixes out-of-bounds slab read accesses made by memcpy() of the hdmi-codec driver. This problem is reported by KASAN.
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Analysis
by VulDB Data Team • 01/07/2025
The vulnerability identified as CVE-2022-48739 represents a critical out-of-bounds memory access flaw within the Linux kernel's audio subsystem, specifically affecting the HDMI codec driver component. This issue manifests in the Advanced Sound Architecture Component framework where the hdmi-codec driver attempts to perform memory operations that exceed the allocated buffer boundaries. The vulnerability was detected through kernel memory debugging mechanisms, with KASAN (Kernel Address Sanitizer) reporting the problematic slab read accesses that occur during memory copy operations.
The technical root cause of this vulnerability stems from a mismatch in array sizing within the audio codec driver implementation. The iec_status array was incorrectly sized, being smaller than the status array of the struct snd_aes_iec958 structure. This dimensional inconsistency creates a scenario where memcpy() operations attempt to read beyond the allocated memory boundaries of the iec_status array, leading to unauthorized memory access patterns. The flaw demonstrates poor buffer management practices and inadequate input validation within the audio driver's memory handling code.
The operational impact of this vulnerability extends beyond simple memory corruption, potentially enabling attackers to exploit the out-of-bounds read conditions for privilege escalation or system instability. When the hdmi-codec driver processes audio data through the HDMI interface, the corrupted memory access patterns could lead to information disclosure, system crashes, or in more severe scenarios, provide a foothold for further exploitation. The vulnerability affects systems running Linux kernels with HDMI audio capabilities, particularly those utilizing the Advanced Sound Architecture framework for audio processing.
Security mitigations for this vulnerability involve applying the kernel patch that correctly aligns the iec_status array size with the status array of the snd_aes_iec958 structure. This fix ensures that all memory copy operations within the hdmi-codec driver remain within properly allocated buffer boundaries. System administrators should prioritize updating to kernel versions containing this patch, as the vulnerability represents a direct threat to system integrity and could potentially be leveraged for privilege escalation attacks. The fix aligns with industry best practices for buffer overflow prevention and memory safety, addressing the core issue identified through kernel security testing mechanisms.
This vulnerability maps to CWE-129, which covers improper validation of array index, and CWE-787, which addresses out-of-bounds write operations. From an ATT&CK perspective, this flaw could be categorized under T1068, which involves exploiting legitimate credentials for privilege escalation, as the memory corruption could potentially enable attackers to gain elevated privileges. The vulnerability also aligns with T1211, which covers exploitation of memory corruption through buffer overflows, making it a significant concern for system security and stability in enterprise environments.