CVE-2022-50870

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> powerpc/rtas: avoid device tree lookups in rtas_os_term()<br /> <br /> rtas_os_term() is called during panic. Its behavior depends on a couple<br /> of conditions in the /rtas node of the device tree, the traversal of<br /> which entails locking and local IRQ state changes. If the kernel panics<br /> while devtree_lock is held, rtas_os_term() as currently written could<br /> hang.<br /> <br /> Instead of discovering the relevant characteristics at panic time,<br /> cache them in file-static variables at boot. Note the lookup for<br /> "ibm,extended-os-term" is converted to of_property_read_bool() since it<br /> is a boolean property, not an RTAS function token.<br /> <br /> [mpe: Incorporate suggested change from Nick]