CVE-2026-64072 in Linux
Summary
by MITRE • 07/19/2026
In the Linux kernel, the following vulnerability has been resolved:
nvme: fix bio leak on mapping failure
The local bio is always NULL, so we'd leak the bio if the integrity mapping failed. Just get it directly from the request.
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Analysis
by VulDB Data Team • 07/19/2026
The vulnerability resides in the linux kernel's nvme subsystem where a critical resource management flaw exists in the block I/O handling mechanism. This issue manifests as a bio (block I/O) leak that occurs during integrity mapping failures within the nvme driver implementation. The root cause stems from improper handling of bio references where the local bio variable is consistently initialized to NULL, creating a scenario where allocated bio structures are not properly released when mapping operations fail. This represents a classic resource leak pattern that can accumulate over time and potentially lead to system instability or denial of service conditions.
The technical flaw specifically involves the nvme driver's request processing pipeline where bio structures are allocated but not correctly freed upon integrity mapping failure conditions. The kernel's block layer manages I/O requests through bio structures that encapsulate data and metadata for disk operations, and when these structures are improperly managed during error paths, they remain allocated in memory even though their associated operations have failed. This particular implementation defect demonstrates poor error handling practices where the driver fails to extract the bio reference directly from the request structure, instead relying on a potentially NULL local variable that has been initialized to zero. The issue is particularly concerning because it operates at the kernel level where resource leaks can have cascading effects on system performance and stability.
The operational impact of this vulnerability extends beyond simple memory consumption as it represents a potential denial of service vector that could degrade system performance or cause complete system instability under sustained I/O load conditions. When bio structures accumulate due to improper cleanup, they consume valuable kernel memory resources that could otherwise be utilized for legitimate I/O operations. The vulnerability affects systems utilizing nvme storage devices where integrity mapping is enabled, potentially impacting enterprise storage environments, cloud infrastructure, and consumer systems with nvme SSDs. This flaw can be exploited by malicious actors who continuously submit nvme requests that trigger the mapping failure path, leading to progressive memory exhaustion and system resource depletion.
Mitigation strategies must focus on implementing proper error handling within the nvme driver's bio management code where the bio reference should be extracted directly from the request structure rather than relying on potentially NULL local variables. The fix involves modifying the driver code to ensure that when integrity mapping fails, the bio structure is properly retrieved from the request context and released appropriately. This aligns with established security practices for kernel development and follows the principle of least privilege where resources are managed correctly regardless of execution path taken. The vulnerability demonstrates the importance of proper resource management in kernel space where failure to release allocated structures can lead to system instability, making it a critical issue that requires immediate attention and patching across affected systems. This type of vulnerability is categorized under CWE-404 as improper resource management and relates to ATT&CK technique T1499.001 for resource exhaustion attacks that target memory allocation patterns in operating system components.