6.12-stable review patch. If anyone has any objections, please let me know.
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From: Kefeng Wang wangkefeng.wang@huawei.com
commit f5d09de9f1bf9674c6418ff10d0a40cfe29268e1 upstream.
In current kernel, hugetlb_wp() calls copy_user_large_folio() with the fault address. Where the fault address may be not aligned with the huge page size. Then, copy_user_large_folio() may call copy_user_gigantic_page() with the address, while copy_user_gigantic_page() requires the address to be huge page size aligned. So, this may cause memory corruption or information leak, addtional, use more obvious naming 'addr_hint' instead of 'addr' for copy_user_gigantic_page().
Link: https://lkml.kernel.org/r/20241028145656.932941-2-wangkefeng.wang@huawei.com Fixes: 530dd9926dc1 ("mm: memory: improve copy_user_large_folio()") Signed-off-by: Kefeng Wang wangkefeng.wang@huawei.com Reviewed-by: David Hildenbrand david@redhat.com Cc: Huang Ying ying.huang@intel.com Cc: Matthew Wilcox (Oracle) willy@infradead.org Cc: Muchun Song muchun.song@linux.dev Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/hugetlb.c | 5 ++--- mm/memory.c | 5 +++-- 2 files changed, 5 insertions(+), 5 deletions(-)
--- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5333,7 +5333,7 @@ again: break; } ret = copy_user_large_folio(new_folio, pte_folio, - ALIGN_DOWN(addr, sz), dst_vma); + addr, dst_vma); folio_put(pte_folio); if (ret) { folio_put(new_folio); @@ -6632,8 +6632,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_ *foliop = NULL; goto out; } - ret = copy_user_large_folio(folio, *foliop, - ALIGN_DOWN(dst_addr, size), dst_vma); + ret = copy_user_large_folio(folio, *foliop, dst_addr, dst_vma); folio_put(*foliop); *foliop = NULL; if (ret) { --- a/mm/memory.c +++ b/mm/memory.c @@ -6817,13 +6817,14 @@ void folio_zero_user(struct folio *folio }
static int copy_user_gigantic_page(struct folio *dst, struct folio *src, - unsigned long addr, + unsigned long addr_hint, struct vm_area_struct *vma, unsigned int nr_pages) { - int i; + unsigned long addr = ALIGN_DOWN(addr_hint, folio_size(dst)); struct page *dst_page; struct page *src_page; + int i;
for (i = 0; i < nr_pages; i++) { dst_page = folio_page(dst, i);