CVE-2025-37788 in Linux
Summary
by MITRE • 05/01/2025
In the Linux kernel, the following vulnerability has been resolved:
cxgb4: fix memory leak in cxgb4_init_ethtool_filters() error path
In the for loop used to allocate the loc_array and bmap for each port, a memory leak is possible when the allocation for loc_array succeeds, but the allocation for bmap fails. This is because when the control flow goes to the label free_eth_finfo, only the allocations starting from (i-1)th iteration are freed.
Fix that by freeing the loc_array in the bmap allocation error path.
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Analysis
by VulDB Data Team • 03/16/2026
The vulnerability identified as CVE-2025-37788 represents a memory leak in the Linux kernel's cxgb4 driver, specifically within the cxgb4_init_ethtool_filters() function. This issue affects network interface controllers using the cxgb4 driver, which is part of the Chelsio Communications driver suite designed for high-performance network adapters. The flaw manifests in the error handling path of a loop that manages memory allocation for port-specific data structures, creating a potential denial of service condition through progressive memory consumption.
The technical implementation of this vulnerability stems from improper error handling in a for loop that iterates through network ports to allocate memory for loc_array and bmap data structures. When the allocation for loc_array succeeds but the subsequent allocation for bmap fails, the existing code structure fails to properly clean up the previously allocated loc_array memory. The control flow jumps to the free_eth_finfo label, which only frees allocations from the previous iteration, leaving the current iteration's loc_array allocation dangling and unrecoverable. This represents a classic memory leak pattern that can accumulate over time and system usage, leading to resource exhaustion.
The operational impact of this vulnerability extends beyond simple memory waste, as it can contribute to system instability and performance degradation in environments where the cxgb4 driver is actively used. Network administrators managing systems with Chelsio network adapters may observe gradual memory consumption increases, potentially leading to system slowdowns or complete memory exhaustion under sustained network traffic loads. The vulnerability affects systems running Linux kernels with the cxgb4 driver, particularly those handling high network throughput or extended operational periods where the leak accumulation becomes significant. This issue aligns with CWE-401, which categorizes memory leaks as a fundamental weakness in software design and implementation practices.
Mitigation strategies for CVE-2025-37788 primarily involve applying the kernel patch that implements proper memory cleanup in the error path by ensuring that loc_array allocations are freed when bmap allocation fails. System administrators should prioritize updating their kernel versions to include the fix, particularly in production environments where network reliability is critical. Additionally, monitoring for memory consumption patterns and implementing automated alerting for unusual memory usage trends can help detect potential exploitation of this vulnerability. The fix aligns with ATT&CK technique T1499.001, which involves resource exhaustion through memory leaks, and represents a fundamental defensive measure against persistent denial of service conditions. Organizations should also consider implementing network monitoring tools to track the health of network interfaces using the affected driver, as memory leaks can manifest as intermittent connectivity issues or performance degradation that may be misdiagnosed as network hardware problems.