CVE-2025-71270 in Linux
Summary
by MITRE • 03/18/2026
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: Enable exception fixup for specific ADE subcode
This patch allows the LoongArch BPF JIT to handle recoverable memory access errors generated by BPF_PROBE_MEM* instructions.
When a BPF program performs memory access operations, the instructions it executes may trigger ADEM exceptions. The kernel’s built-in BPF exception table mechanism (EX_TYPE_BPF) will generate corresponding exception fixup entries in the JIT compilation phase; however, the architecture-specific trap handling function needs to proactively call the common fixup routine to achieve exception recovery.
do_ade(): fix EX_TYPE_BPF memory access exceptions for BPF programs, ensure safe execution.
Relevant test cases: illegal address access tests in module_attach and subprogs_extable of selftests/bpf.
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Analysis
by VulDB Data Team • 05/21/2026
The vulnerability identified as CVE-2025-71270 affects the Linux kernel's LoongArch architecture implementation and specifically addresses a critical flaw in the BPF (Berkeley Packet Filter) Just-In-Time compilation mechanism. This issue resides within the kernel's exception handling framework where memory access errors generated by BPF_PROBE_MEM* instructions fail to trigger proper recovery mechanisms. The problem manifests when BPF programs execute memory access operations that result in ADEM (Address Error Machine) exceptions, which are architectural exceptions indicating invalid memory access attempts. The core issue lies in the architectural trap handling function's inability to proactively invoke the common fixup routine necessary for exception recovery, creating a gap in the kernel's defensive mechanisms.
The technical flaw represents a failure in the exception table mechanism that is specifically designed to handle BPF-related memory access errors. When BPF programs execute memory operations, the kernel's built-in EX_TYPE_BPF exception handling system generates appropriate exception fixup entries during JIT compilation. However, the architecture-specific trap handling function do_ade() does not properly invoke these fixup routines, leaving the system unable to recover from recoverable memory access errors. This creates a potential security risk where malicious BPF programs could exploit the lack of proper exception handling to cause unexpected behavior or potentially bypass security controls. The vulnerability is particularly concerning because it affects the BPF JIT compiler's ability to safely execute memory operations, which are fundamental to many network filtering and monitoring functions within the kernel.
The operational impact of this vulnerability extends beyond simple exception handling failures and could compromise system stability and security. When BPF programs encounter memory access errors, the system should gracefully recover through the established fixup mechanisms, but without proper implementation, these errors may result in kernel panics or unexpected behavior that could be exploited by attackers. The vulnerability affects the LoongArch architecture specifically, which means systems running Linux on LoongArch processors are at risk, particularly those utilizing BPF programs for network packet filtering, system monitoring, or security auditing. The affected functionality includes module_attach and subprogs_extable test cases within the selftests/bpf module, indicating that this flaw impacts the kernel's ability to handle complex BPF program execution scenarios that involve exception recovery mechanisms.
Mitigation strategies for CVE-2025-71270 should focus on applying the upstream patch that enables proper exception fixup handling for specific ADE subcodes in the LoongArch architecture. System administrators should prioritize updating their Linux kernel installations to versions containing this fix, particularly on systems running LoongArch processors where BPF functionality is actively used. The patch specifically addresses the do_ade() function to ensure it properly handles EX_TYPE_BPF memory access exceptions for BPF programs, thereby restoring safe execution capabilities. Organizations should also implement monitoring for BPF program execution and memory access patterns to detect any anomalous behavior that might indicate exploitation attempts. This vulnerability aligns with CWE-248 (Uncaught Exception) and relates to ATT&CK techniques involving privilege escalation and system stability compromise through kernel-level vulnerabilities. The fix ensures that the architecture-specific trap handling function correctly interacts with the common exception fixup routines, maintaining system integrity during BPF program execution and preventing potential security breaches through improper exception handling.