CVE-2023-53778: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-53778 is an integer overflow vulnerability in the Linux kernel's accel/qaic subsystem, specifically within the map_user_pages() and encode_dma() functions. The flaw involves insufficient integer overflow checking when handling DMA transfer size and address calculations, which could lead to unsafe memory operations. It affects the Linux kernel and was published on December 9, 2025. The vulnerability is estimated to be of Medium severity, with an EPSS score of 0.018% (Feedly).

The root cause is improper integer overflow validation (CWE-190) in the map_user_pages() function of the accel/qaic driver. Specifically, the encode_dma() function checked that in_trans->addr + in_trans->size did not overflow, but the logic was fragmented and error-prone. The fix introduces a remaining variable representing bytes left to transfer (in_trans->size - resources->xferred_dma_size), adds a check that in_trans->size is not less than resources->xferred_dma_size (which would imply a negative remainder), and validates address arithmetic in parts to prevent overflow. Exploitation would require local access to a system with the QAIC accelerator driver loaded and the ability to submit crafted DMA transfer requests (Feedly).

A successful exploit of this vulnerability could allow a local attacker to trigger integer overflow conditions in DMA address/size calculations within the QAIC accelerator driver, potentially leading to out-of-bounds memory access, kernel memory corruption, or system instability. The impact is primarily on integrity and availability of the kernel, with a limited scope confined to systems using the Qualcomm AI Cloud (QAIC) accelerator hardware and its associated driver (Feedly).

There is no known public proof-of-concept exploit or evidence of in-the-wild exploitation for CVE-2023-53778. The vulnerability has an EPSS score of approximately 0.018%, indicating a very low probability of exploitation in the near term. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. Exploitation requires local access and a system equipped with the QAIC accelerator, significantly limiting the attack surface (Feedly).

The fix has been committed to the Linux kernel stable tree via patches at git.kernel.org (commits 96d3c1ca and d410a96e). Users should update to a patched kernel version that includes these commits. SUSE has issued advisories (SUSE-2026-0281-1 and SUSE-2026-20876-1) incorporating the fix for affected SUSE Linux Enterprise kernel packages. Administrators running systems with the QAIC accelerator driver should prioritize applying the relevant kernel update from their distribution vendor (Feedly, Linux Security).