6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: David Hildenbrand david@redhat.com
commit 4a5e85f4eb8fd18b1266342d100e4f0849544ca0 upstream.
is_zero_pfn() does not work for the huge zero folio. Fix it by using is_huge_zero_pmd().
This can cause the PAGEMAP_SCAN ioctl against /proc/pid/pagemap to present pages as PAGE_IS_PRESENT rather than as PAGE_IS_PFNZERO.
Found by code inspection.
Link: https://lkml.kernel.org/r/20250617143532.2375383-1-david@redhat.com Fixes: 52526ca7fdb9 ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs") Signed-off-by: David Hildenbrand david@redhat.com Cc: Muhammad Usama Anjum usama.anjum@collabora.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/proc/task_mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -2155,7 +2155,7 @@ static unsigned long pagemap_thp_categor categories |= PAGE_IS_FILE; }
- if (is_zero_pfn(pmd_pfn(pmd))) + if (is_huge_zero_pmd(pmd)) categories |= PAGE_IS_PFNZERO; if (pmd_soft_dirty(pmd)) categories |= PAGE_IS_SOFT_DIRTY;