Executive Summary

This vulnerability exists in the Linux kernel's Realtek rtlwifi PCI driver. It involves a use-after-free condition caused by an unfinished irq_prepare_bcn_tasklet. Specifically, the irq_prepare_bcn_tasklet is initialized and scheduled when a hardware interrupt occurs, but it is not properly terminated when the rtlwifi card is detached or its probe fails. As a result, the tasklet may still run or be pending after the ieee80211_hw structure it accesses has been freed, leading to a use-after-free scenario.

The fix involves adding a tasklet_kill() call in the rtl_pci_deinit() function to ensure the irq_prepare_bcn_tasklet is properly stopped before the ieee80211_hw is released.

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Impact Analysis

This use-after-free vulnerability can lead to undefined behavior in the Linux kernel, such as system crashes, memory corruption, or potential escalation of privileges if exploited. Since the tasklet may access freed memory, it could cause instability or allow an attacker to execute arbitrary code within the kernel context, depending on the exploitation scenario.

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Mitigation Strategies

The vulnerability is fixed by ensuring that the irq_prepare_bcn_tasklet is properly terminated before the ieee80211_hw is released. This is done by adding tasklet_kill() in rtl_pci_deinit().

To mitigate this vulnerability, you should update your Linux kernel to a version that includes this fix.

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Detection Guidance

This vulnerability was identified through static analysis and involves a use-after-free condition in the rtlwifi driver related to the irq_prepare_bcn_tasklet not being properly killed during device deinitialization.

There are no specific detection commands or network/system detection methods provided in the available information.

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