CVE-2025-37949 xenbus: Use kref to track req lifetime

In the Linux kernel, the following vulnerability has been resolved: xenbus: Use kref to track req lifetime Marek reported seeing a NULL pointer fault in the xenbusthread callstack: BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: e030:wakeupcommon+0x4c/0x180 Call Trace:...

CVE-2025-37949

CVE-2025-37949 concerns the Linux kernel XenBus code. The connected docs describe a NULL pointer dereference in xenbus_thread caused by a wake-up path where req may be freed before resuming, and the fix adds two separate kref lifetimes (one for the caller and one for xenbus_thread) with kref_put(...