CVE-2026-72270 in Linux
Summary
by MITRE • 08/15/2026
In the Linux kernel, the following vulnerability has been resolved:
fbdev: s3fb: fix potential memory leak in s3_pci_probe()
In s3_pci_probe(), the memory allocated for modelist using fb_videomode_to_modelist() is not freed in subsequent error paths. Fix that by calling fb_destroy_modelist()
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Analysis
by VulDB Data Team • 08/15/2026
The vulnerability identified in the Linux kernel's framebuffer device subsystem affects the s3fb driver, which handles display hardware compatibility for S3 graphics chips. This memory leak occurs within the s3_pci_probe() function where video mode information is dynamically allocated to support various display resolutions and refresh rates. The fb_videomode_to_modelist() function creates a linked list structure containing video mode definitions that are essential for proper display functionality, but when error conditions occur during driver initialization, this allocated memory is not properly released back to the system.
The technical flaw stems from inadequate error handling within the driver's probe function where multiple exit paths exist after memory allocation. When the s3_pci_probe() function encounters issues such as hardware detection failures, resource conflicts, or configuration errors, it follows alternative code paths that bypass the proper cleanup routine. This violates fundamental memory management principles and creates a persistent memory leak that accumulates over time as the driver attempts to initialize on different hardware configurations. The vulnerability specifically relates to CWE-401 Memory Leak, which is classified under the Common Weakness Enumeration catalog for improper resource management.
The operational impact of this memory leak can be significant in systems where multiple framebuffer drivers are loaded or when devices with S3 graphics chips are frequently connected and disconnected from the system. Over time, repeated initialization attempts without proper cleanup will consume increasing amounts of system memory, potentially leading to performance degradation, system instability, or even out-of-memory conditions that could affect other critical system processes. This issue is particularly concerning in embedded systems or server environments where long-running processes and frequent hardware interactions are common.
Mitigation strategies for this vulnerability involve implementing proper error handling within the s3_pci_probe() function by ensuring that fb_destroy_modelist() is called whenever the driver exits through error paths after memory allocation has occurred. System administrators should ensure their Linux kernels are updated to versions containing this fix, as the patch typically involves adding cleanup calls in all conditional exit branches of the probe function. Additionally, monitoring system memory usage and implementing regular kernel updates as part of security maintenance procedures will help prevent exploitation of such memory management vulnerabilities. The fix aligns with ATT&CK technique T1070.004 Indicator Removal on Host by ensuring proper resource cleanup and preventing persistent memory consumption that could mask other security issues or impact system stability through resource exhaustion.