CVE-2026-74279 in Linux
Summary
by MITRE • 08/15/2026
In the Linux kernel, the following vulnerability has been resolved:
crypto: cavium/cpt - fix DMA cleanup using wrong loop index
The sg_cleanup error path used list[i] instead of list[j] when unmapping
DMA buffers, leaking successfully mapped entries and repeatedly unmapping the failed one.
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Analysis
by VulDB Data Team • 08/15/2026
This vulnerability resides within the Linux kernel's cryptographic subsystem, specifically affecting the Cavium Cryptographic Processing Unit (CPT) driver implementation. The issue manifests in the DMA buffer management routines where improper loop indexing causes critical resource leakage during error handling scenarios. The flaw occurs when processing scatter-gather lists for cryptographic operations, creating a condition where successfully mapped DMA buffers remain unreleased while the failed entry gets repeatedly unmapped. This fundamental indexing error represents a classic software defect that violates proper memory management protocols and can lead to system instability or resource exhaustion.
The technical implementation flaw stems from incorrect variable usage within the cleanup loop structure of the scatter-gather buffer handling code. When the cryptographic driver encounters an error during DMA mapping operations, it attempts to clean up previously mapped buffers through the sg_cleanup function. However, the loop iteration variable i is incorrectly used instead of j, causing the cleanup routine to reference memory locations outside the intended scope. This indexing mistake creates a scenario where the driver processes the wrong list entries during error recovery, leading to partial buffer leakage and redundant unmapping operations that can ultimately cause system resource depletion.
The operational impact of this vulnerability extends beyond simple memory leaks to potentially compromise system stability and performance in cryptographic workloads. When multiple concurrent cryptographic operations occur, particularly under high load conditions, the continuous leakage of DMA buffers can gradually consume available system resources. This degradation manifests as reduced system responsiveness, increased latency in cryptographic processing, and in severe cases, complete system lockup or crash due to resource exhaustion. The vulnerability affects systems utilizing Cavium CPT hardware accelerators where cryptographic operations are performed through the kernel's crypto API framework.
Mitigation strategies should focus on immediate code correction through proper loop variable indexing and comprehensive testing of error paths within the cryptographic subsystem. System administrators should prioritize applying kernel updates that contain the corrected implementation, ensuring that all cryptographic operations involving Cavium CPT hardware receive the necessary patches. Additionally, monitoring systems should be enhanced to detect unusual resource consumption patterns during cryptographic workloads, providing early warning of potential buffer leakage conditions. The vulnerability aligns with CWE-129 and CWE-457 categories related to improper input validation and use of uninitialized variables, while also presenting characteristics consistent with ATT&CK technique T1070 for indicator removal through manipulation of system logs or resource management functions.