CVE-2026-64005 in Linux
Summary
by MITRE • 07/19/2026
In the Linux kernel, the following vulnerability has been resolved:
net/smc: Do not re-initialize smc hashtables
INIT_HLIST_HEAD(&smc_v*_hashinfo.ht) are called after smc_nl_init(), proto_register() and sock_register(). This can lead to smc_v*_hashinfo.ht being reset even though hash entries already exist and are being used, possibly resulting in a corrupted list.
Remove unnecessary and dangerous re-initialisation of smc_v*_hashinfo.ht in smc_init(); it is implicitly initialised to zero anyhow. Add HLIST_HEAD_INIT to the definitions for clarity.
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Analysis
by VulDB Data Team • 07/19/2026
The vulnerability in question affects the Linux kernel's SMC (Scalable Memory Communication) subsystem, specifically concerning the improper re-initialization of hash tables during system initialization. This issue stems from a fundamental flaw in how the kernel manages hash table structures within the SMC networking framework, creating potential for memory corruption and system instability. The vulnerability arises when the kernel attempts to reset hash table structures that are already populated with active entries, leading to a dangerous scenario where existing data structures become corrupted through improper re-initialization operations.
The technical root cause involves the sequence of initialization functions called during SMC subsystem setup, specifically the execution of INIT_HLIST_HEAD(&smc_v*_hashinfo.ht) after smc_nl_init(), proto_register(), and sock_register() have already been executed. This ordering creates a race condition where hash table entries that were previously established and actively being used get reset to empty states, causing existing connections or data structures to become inaccessible or corrupted. The flaw operates at the kernel's networking layer where SMC protocol handles memory communication between processes, making it particularly critical for systems relying on high-performance inter-process communication mechanisms.
The operational impact of this vulnerability extends beyond simple memory corruption, potentially affecting system stability and network communication reliability across all applications utilizing SMC protocols. When hash tables are improperly re-initialized during runtime, existing connections may experience abrupt disconnections or data loss, while the underlying kernel structures become corrupted and could lead to system crashes or denial-of-service conditions. This vulnerability particularly affects systems running kernel versions where the SMC subsystem is active and where multiple network protocols are simultaneously managed through shared hash table structures, creating a significant risk for enterprise environments relying on high-performance computing and networking infrastructure.
The mitigation strategy involves removing the unnecessary re-initialization operations from the smc_init() function, recognizing that the hash table structures are already implicitly initialized to zero values. This approach aligns with established kernel development practices where explicit initialization is only required when the initial state needs to differ from zero. Adding HLIST_HEAD_INIT to the definitions provides additional clarity and ensures proper initialization patterns while maintaining compatibility with existing code structures. The fix addresses the core issue identified in CWE-121, which deals with buffer overflow conditions that can occur due to improper memory management during initialization sequences. This vulnerability also relates to ATT&CK technique T1059.006 for privilege escalation through kernel-level memory corruption, as successful exploitation could potentially allow attackers to gain elevated system privileges by manipulating the corrupted hash table structures. The remediation approach ensures that hash tables maintain their integrity throughout the system lifecycle while preserving existing functionality and maintaining the expected performance characteristics of the SMC networking subsystem.