CVE-2024-39495

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> greybus: Fix use-after-free bug in gb_interface_release due to race condition.<br /> <br /> In gb_interface_create, &amp;intf-&gt;mode_switch_completion is bound with<br /> gb_interface_mode_switch_work. Then it will be started by<br /> gb_interface_request_mode_switch. Here is the relevant code.<br /> if (!queue_work(system_long_wq, &amp;intf-&gt;mode_switch_work)) {<br /> ...<br /> }<br /> <br /> If we call gb_interface_release to make cleanup, there may be an<br /> unfinished work. This function will call kfree to free the object<br /> "intf". However, if gb_interface_mode_switch_work is scheduled to<br /> run after kfree, it may cause use-after-free error as<br /> gb_interface_mode_switch_work will use the object "intf".<br /> The possible execution flow that may lead to the issue is as follows:<br /> <br /> CPU0 CPU1<br /> <br /> | gb_interface_create<br /> | gb_interface_request_mode_switch<br /> gb_interface_release |<br /> kfree(intf) (free) |<br /> | gb_interface_mode_switch_work<br /> | mutex_lock(&amp;intf-&gt;mutex) (use)<br /> <br /> Fix it by canceling the work before kfree.