pagemap_pmd_range_thp() assumes that every non-present PMD is a migration entry and unconditionally calls softleaf_to_page(). This will crash on any non-present PMD type that does not encode a PFN, such as the upcoming PMD-level swap entries. Guard the page lookup with softleaf_has_pfn(), matching how pte_to_pagemap_entry() already handles non-present PTEs. Acked-by: David Hildenbrand (Arm) Reviewed-by: Zi Yan Signed-off-by: Usama Arif --- fs/proc/task_mmu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index d32408f7cd5e..1fb5acd88ad0 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -2129,7 +2129,8 @@ static int pagemap_pmd_range_thp(pmd_t *pmdp, unsigned long addr, flags |= PM_SOFT_DIRTY; if (pmd_swp_uffd_wp(pmd)) flags |= PM_UFFD_WP; - page = softleaf_to_page(entry); + if (softleaf_has_pfn(entry)) + page = softleaf_to_page(entry); } if (page) { -- 2.53.0-Meta