From: Kirill A. Shutemov Date: Wed, 9 Apr 2025 09:40:43 +0000 (+0300) Subject: mm: fix apply_to_existing_page_range() X-Git-Tag: v6.15-rc3~43^2~1 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a995199384347261bb3f21b2e171fa7f988bd2f8;p=thirdparty%2Fkernel%2Flinux.git mm: fix apply_to_existing_page_range() In the case of apply_to_existing_page_range(), apply_to_pte_range() is reached with 'create' set to false. When !create, the loop over the PTE page table is broken. apply_to_pte_range() will only move to the next PTE entry if 'create' is true or if the current entry is not pte_none(). This means that the user of apply_to_existing_page_range() will not have 'fn' called for any entries after the first pte_none() in the PTE page table. Fix the loop logic in apply_to_pte_range(). There are no known runtime issues from this, but the fix is trivial enough for stable@ even without a known buggy user. Link: https://lkml.kernel.org/r/20250409094043.1629234-1-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov Fixes: be1db4753ee6 ("mm/memory.c: add apply_to_existing_page_range() helper") Cc: Daniel Axtens Cc: David Hildenbrand Cc: Vlastimil Babka Cc: Signed-off-by: Andrew Morton --- diff --git a/mm/memory.c b/mm/memory.c index 1a35165622e1c..44481fe7c629e 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2938,11 +2938,11 @@ static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd, if (fn) { do { if (create || !pte_none(ptep_get(pte))) { - err = fn(pte++, addr, data); + err = fn(pte, addr, data); if (err) break; } - } while (addr += PAGE_SIZE, addr != end); + } while (pte++, addr += PAGE_SIZE, addr != end); } *mask |= PGTBL_PTE_MODIFIED;