NULL Pointer Dereference Affecting kernel-rt-debug package, versions *

Note: Versions mentioned in the description apply only to the upstream kernel-rt-debug package and not the kernel-rt-debug package as distributed by Centos. See How to fix? for Centos:7 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

usb: dwc3: gadget: Fix NULL pointer dereference in dwc3_gadget_suspend

In current scenario if Plug-out and Plug-In performed continuously there could be a chance while checking for dwc->gadget_driver in dwc3_gadget_suspend, a NULL pointer dereference may occur.

Call Stack:

CPU1:                           CPU2:
gadget_unbind_driver            dwc3_suspend_common
dwc3_gadget_stop                dwc3_gadget_suspend
                                    dwc3_disconnect_gadget

CPU1 basically clears the variable and CPU2 checks the variable. Consider CPU1 is running and right before gadget_driver is cleared and in parallel CPU2 executes dwc3_gadget_suspend where it finds dwc->gadget_driver which is not NULL and resumes execution and then CPU1 completes execution. CPU2 executes dwc3_disconnect_gadget where it checks dwc->gadget_driver is already NULL because of which the NULL pointer deference occur.

• https://access.redhat.com/security/cve/CVE-2024-26715
• https://git.kernel.org/stable/c/36695d5eeeefe5a64b47d0336e7c8fc144e78182
• https://git.kernel.org/stable/c/57e2e42ccd3cd6183228269715ed032f44536751
• https://git.kernel.org/stable/c/61a348857e869432e6a920ad8ea9132e8d44c316
• https://git.kernel.org/stable/c/88936ceab6b426f1312327e9ef849c215c6007a7
• https://git.kernel.org/stable/c/c7ebd8149ee519d27232e6e4940e9c02071b568b