In the Linux kernel, the following vulnerability has been resolved: mm: avoid leaving partial pfn mappings around in error case As Jann points out, PFN mappings are special, because unlike normal m…

Summary

In the Linux kernel, the following vulnerability has been resolved: mm: avoid leaving partial pfn mappings around in error case As Jann points out, PFN mappings are special, because unlike normal memory mappings, there is no lifetime information associated with the mapping - it is just a raw mapping of PFNs with no reference counting of a 'struct page'. That's all very much intentional, but it does mean that it's easy to mess up the cleanup in case of errors. Yes, a failed mmap() will alway…