CVE-2023-52790 in Linux
Summary
by MITRE • 05/21/2024
In the Linux kernel, the following vulnerability has been resolved:
swiotlb: fix out-of-bounds TLB allocations with CONFIG_SWIOTLB_DYNAMIC
Limit the free list length to the size of the IO TLB. Transient pool can be smaller than IO_TLB_SEGSIZE, but the free list is initialized with the assumption that the total number of slots is a multiple of IO_TLB_SEGSIZE. As a result, swiotlb_area_find_slots() may allocate slots past the end of a transient IO TLB buffer.
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Analysis
by VulDB Data Team • 09/24/2025
The vulnerability identified as CVE-2023-52790 represents a critical memory management flaw within the Linux kernel's software I/O translation lookaside buffer implementation. This issue specifically affects systems utilizing the CONFIG_SWIOTLB_DYNAMIC configuration option, which enables dynamic allocation of I/O TLB buffers for handling DMA operations. The vulnerability stems from an improper boundary check during the allocation process, creating a potential for out-of-bounds memory access that could be exploited to compromise system integrity. The flaw manifests when the kernel attempts to manage I/O TLB segments through the swiotlb_area_find_slots() function, which fails to properly account for the actual buffer size limits during allocation operations.
The technical root cause of this vulnerability lies in the mismatch between the expected and actual free list length calculations within the software I/O TLB subsystem. When transient pools are initialized, they may contain fewer slots than the predefined IO_TLB_SEGSIZE value, yet the free list initialization assumes all segments maintain the full size multiple. This fundamental assumption leads to incorrect memory boundary calculations during slot allocation, allowing the swiotlb_area_find_slots() function to potentially allocate memory slots beyond the legitimate boundaries of the transient IO TLB buffer. The flaw operates at the kernel level where memory management operations are critical for system stability and security, making it particularly dangerous as it can lead to memory corruption or unauthorized memory access patterns. This vulnerability directly relates to CWE-129 and CWE-787, which address improper bounds checking and out-of-bounds read/write operations in memory management contexts.
The operational impact of CVE-2023-52790 extends beyond simple memory corruption, potentially enabling privilege escalation attacks and system instability. When exploited, this vulnerability could allow malicious actors to corrupt kernel memory structures, leading to system crashes, data corruption, or unauthorized access to sensitive system resources. The attack surface is particularly concerning for servers and embedded systems that heavily utilize DMA operations, as these environments are more likely to trigger the vulnerable code path during normal operation. The transient nature of the vulnerability means that exploitation could occur during routine I/O operations, making detection and prevention challenging. Systems utilizing virtualization technologies or those with complex DMA configurations are especially at risk, as these environments typically involve more frequent and complex I/O TLB management operations that increase the likelihood of triggering the flawed allocation logic.
Mitigation strategies for CVE-2023-52790 require immediate kernel updates addressing the specific memory boundary calculation issue within the swiotlb subsystem. System administrators should prioritize patching affected kernel versions, particularly those implementing CONFIG_SWIOTLB_DYNAMIC, as this vulnerability can be exploited to gain elevated privileges or cause system instability. The fix involves implementing proper bounds checking within the swiotlb_area_find_slots() function to ensure that free list length calculations respect the actual IO TLB buffer sizes rather than relying on the incorrect assumption about segment size multiples. Organizations should also consider monitoring system logs for unusual memory allocation patterns or DMA-related errors that might indicate exploitation attempts. Additionally, implementing runtime protections such as kernel address space layout randomization and memory protection mechanisms can provide additional defense layers against potential exploitation attempts. The vulnerability aligns with ATT&CK technique T1068 which involves exploiting local privilege escalation opportunities, making it particularly relevant for organizations implementing security frameworks that focus on kernel-level attack surface reduction and privilege control mechanisms.