CVE-2024-44980 in Linux
Summary
by MITRE • 09/04/2024
In the Linux kernel, the following vulnerability has been resolved:
drm/xe: Fix opregion leak
Being part o the display, ideally the setup and cleanup would be done by display itself. However this is a bigger refactor that needs to be done on both i915 and xe. For now, just fix the leak:
unreferenced object 0xffff8881a0300008 (size 192): comm "modprobe", pid 4354, jiffies 4295647021 hex dump (first 32 bytes): 00 00 87 27 81 88 ff ff 18 80 9b 00 00 c9 ff ff ...'............ 18 81 9b 00 00 c9 ff ff 00 00 00 00 00 00 00 00 ................ backtrace (crc 99260e31): [] kmemleak_alloc+0x4b/0x80
[] kmalloc_trace_noprof+0x312/0x3d0
[] intel_opregion_setup+0x89/0x700 [xe]
[] xe_display_init_noirq+0x2f/0x90 [xe]
[] xe_device_probe+0x7a3/0xbf0 [xe]
[] xe_pci_probe+0x333/0x5b0 [xe]
[] local_pci_probe+0x48/0xb0
[] pci_device_probe+0xc8/0x280
[] really_probe+0xf8/0x390
[] __driver_probe_device+0x8a/0x170
[] driver_probe_device+0x23/0xb0
[] __driver_attach+0xc7/0x190
[] bus_for_each_dev+0x7d/0xd0
[] driver_attach+0x1e/0x30
[] bus_add_driver+0x117/0x250
(cherry picked from commit 6f4e43a2f771b737d991142ec4f6d4b7ff31fbb4)
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Analysis
by VulDB Data Team • 12/13/2024
The vulnerability identified as CVE-2024-44980 represents a memory leak within the Linux kernel's graphics display subsystem, specifically affecting the xe driver implementation. This issue occurs in the display runtime environment where the kernel fails to properly clean up allocated memory resources during device initialization phases. The leak manifests as an unreferenced object of 192 bytes size that remains allocated in memory even after the display subsystem has completed its setup operations. The memory leak is particularly concerning as it represents a resource exhaustion risk that could degrade system performance over time, especially in systems with frequent device probing or multiple display operations.
The technical flaw stems from improper resource management within the display initialization path of the xe driver. The kernel's memory leak detection system identified that an object allocated during the intel_opregion_setup function remains unreferenced and unreleased during the xe_display_init_noirq initialization sequence. This pattern of memory allocation without corresponding deallocation violates fundamental memory management principles and creates a persistent memory footprint that accumulates over system operations. The vulnerability is categorized under CWE-401 as a failure to release memory resources, which directly impacts system stability and resource utilization. The backtrace analysis shows the allocation path originating from the kmemleak_alloc function through kmalloc_trace_noprof, indicating that the memory allocation occurs without proper tracking or cleanup mechanisms during the display subsystem initialization process.
The operational impact of this vulnerability extends beyond simple memory consumption as it affects the overall reliability and performance of systems utilizing the xe graphics driver. Memory leaks in kernel space can lead to progressive system degradation where available memory becomes increasingly constrained, potentially causing system instability, reduced responsiveness, or even system crashes under memory pressure conditions. The leak specifically occurs during device probing operations which are frequent in dynamic environments where devices are hot-plugged or reconfigured. This vulnerability is particularly relevant in enterprise and embedded systems where long-running processes and frequent device interactions are common, as the accumulated memory waste can significantly impact system longevity and performance. The issue affects systems using the xe driver for graphics display operations and can be classified under ATT&CK technique T1490 for resource exhaustion, as the leak consumes system resources without proper cleanup.
The mitigation approach for this vulnerability involves implementing proper resource cleanup mechanisms during the display subsystem initialization process. The fix addresses the immediate memory leak by ensuring that allocated objects are properly released during the device setup sequence, rather than allowing them to remain unreferenced in memory. This represents a targeted patch to the existing codebase rather than a fundamental architectural redesign, which aligns with the development approach of addressing the immediate issue while maintaining backward compatibility. The fix follows established kernel development practices by ensuring that all allocated memory within the display initialization path is properly managed through corresponding deallocation routines. System administrators should apply the kernel patch that includes this fix to prevent memory accumulation and maintain optimal system performance, particularly in environments where graphics display operations are frequent or where system resources are constrained. The resolution demonstrates the importance of proper resource management in kernel space and highlights the need for comprehensive memory leak detection and prevention mechanisms in graphics subsystems.