Description
In the Linux kernel, the following vulnerability has been resolved: mm/userfaultfd: reset ptes when close() for wr-protected ones Userfaultfd unregister includes a step to remove wr-protect bits from all the relevant pgtable entries, but that only covered an explicit UFFDIO_UNREGISTER ioctl, not a close() on the userfaultfd itself. Cover that too. This fixes a WARN trace. The only user visible side effect is the user can observe leftover wr-protect bits even if the user close()ed on an userfaultfd when releasing the last reference of it. However hopefully that should be harmless, and nothing bad should happen even if so. This change is now more important after the recent page-table-check patch we merged in mm-unstable (446dd9ad37d0 ("mm/page_table_check: support userfault wr-protect entries")), as we'll do sanity check on uffd-wp bits without vma context. So it's better if we can 100% guarantee no uffd-wp bit leftovers, to make sure each report will be valid.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
f369b07c861435bd812a9d14493f71b34132ed6f to < 1da0471de653b13c8f63dcd32a23574d683c8310affectedf369b07c861435bd812a9d14493f71b34132ed6f to < 377f3a9a3d032a52325a5b110379a25dd1ab1931affectedf369b07c861435bd812a9d14493f71b34132ed6f to < 8d8b68a5b0c9fb23d37df06bb273ead38fd5a29daffectedf369b07c861435bd812a9d14493f71b34132ed6f to < c88033efe9a391e72ba6b5df4b01d6e628f4e734affected3e2747c3ddfa717697c3cc2aa6ab989e48d6587daffected5.19.6 to < 5.20affected
Linux Linux
Default version status: affected
6.0affected0 to < 6.0unaffected6.1.191 to ≤ 6.1.*unaffected6.6.31 to ≤ 6.6.*unaffected6.8.10 to ≤ 6.8.*unaffected6.9 to ≤ *unaffected