In the Linux kernel, the following vulnerability has been resolved: block: bio-integrity: Fix null-ptr-deref in bio_integrity_map_user() pin_user_pages_fast() can partially succeed and return the n…

Summary

In the Linux kernel, the following vulnerability has been resolved: block: bio-integrity: Fix null-ptr-deref in bio_integrity_map_user() pin_user_pages_fast() can partially succeed and return the number of pages that were actually pinned. However, the bio_integrity_map_user() does not handle this partial pinning. This leads to a general protection fault since bvec_from_pages() dereferences an unpinned page address, which is 0. To fix this, add a check to verify that all requested memory is p…