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When hugetlb_vmdelete_list() processes VMAs during truncate operations, it may encounter VMAs where huge_pmd_unshare() is called without the required shareable lock. This triggers an assertion failure in hugetlb_vma_assert_locked(). The previous fix in commitdd83609b88("hugetlbfs: skip VMAs without shareable locks in hugetlb_vmdelete_list") skipped entire VMAs without shareable locks to avoid the assertion. However, this prevented pages from being unmapped and freed, causing a regression in fallocate(PUNCH_HOLE) operations where pages were not freed immediately, as reported by Mark Brown. Instead of checking locks in the caller or skipping VMAs, move the lock assertions in huge_pmd_unshare() to after the early return checks. The assertions are only needed when actual PMD unsharing work will be performed. If the function returns early because sz != PMD_SIZE or the PMD is not shared, no locks are required and assertions should not fire. This approach reverts the VMA skipping logic from commitdd83609b88("hugetlbfs: skip VMAs without shareable locks in hugetlb_vmdelete_list") while moving the assertions to avoid the assertion failure, keeping all the logic within huge_pmd_unshare() itself and allowing page unmapping and freeing to proceed for all VMAs. Link: https://lkml.kernel.org/r/20251014113344.21194-1-kartikey406@gmail.com Fixes:dd83609b88("hugetlbfs: skip VMAs without shareable locks in hugetlb_vmdelete_list") Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com> Reported-by: <syzbot+f26d7c75c26ec19790e7@syzkaller.appspotmail.com> Reported-by: Mark Brown <broonie@kernel.org> Closes: https://syzkaller.appspot.com/bug?extid=f26d7c75c26ec19790e7 Suggested-by: David Hildenbrand <david@redhat.com> Suggested-by: Oscar Salvador <osalvador@suse.de> Tested-by: <syzbot+f26d7c75c26ec19790e7@syzkaller.appspotmail.com> Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>