The quilt patch titled Subject: mm: fix possible OOB in numa_rebuild_large_mapping() has been removed from the -mm tree. Its filename was mm-fix-possible-oob-in-numa_rebuild_large_mapping.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> Subject: mm: fix possible OOB in numa_rebuild_large_mapping() Date: Wed, 12 Jun 2024 20:28:22 +0800 The large folio is mapped with folio size(not greater PMD_SIZE) aligned virtual address during the pagefault, ie, 'addr = ALIGN_DOWN(vmf->address, nr_pages * PAGE_SIZE)' in do_anonymous_page(). But after the mremap(), the virtual address only requires PAGE_SIZE alignment. Also pte is moved to new in move_page_tables(), then traversal of the new pte in the numa_rebuild_large_mapping() could hit the following issue, Unable to handle kernel paging request at virtual address 00000a80c021a788 Mem abort info: ESR = 0x0000000096000004 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x04: level 0 translation fault Data abort info: ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 user pgtable: 4k pages, 48-bit VAs, pgdp=00002040341a6000 [00000a80c021a788] pgd=0000000000000000, p4d=0000000000000000 Internal error: Oops: 0000000096000004 [#1] SMP ... CPU: 76 PID: 15187 Comm: git Kdump: loaded Tainted: G W 6.10.0-rc2+ #209 Hardware name: Huawei TaiShan 2280 V2/BC82AMDD, BIOS 1.79 08/21/2021 pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : numa_rebuild_large_mapping+0x338/0x638 lr : numa_rebuild_large_mapping+0x320/0x638 sp : ffff8000b41c3b00 x29: ffff8000b41c3b30 x28: ffff8000812a0000 x27: 00000000000a8000 x26: 00000000000000a8 x25: 0010000000000001 x24: ffff20401c7170f0 x23: 0000ffff33a1e000 x22: 0000ffff33a76000 x21: ffff20400869eca0 x20: 0000ffff33976000 x19: 00000000000000a8 x18: ffffffffffffffff x17: 0000000000000000 x16: 0000000000000020 x15: ffff8000b41c36a8 x14: 0000000000000000 x13: 205d373831353154 x12: 5b5d333331363732 x11: 000000000011ff78 x10: 000000000011ff10 x9 : ffff800080273f30 x8 : 000000320400869e x7 : c0000000ffffd87f x6 : 00000000001e6ba8 x5 : ffff206f3fb5af88 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000000 x1 : fffffdffc0000000 x0 : 00000a80c021a780 Call trace: numa_rebuild_large_mapping+0x338/0x638 do_numa_page+0x3e4/0x4e0 handle_pte_fault+0x1bc/0x238 __handle_mm_fault+0x20c/0x400 handle_mm_fault+0xa8/0x288 do_page_fault+0x124/0x498 do_translation_fault+0x54/0x80 do_mem_abort+0x4c/0xa8 el0_da+0x40/0x110 el0t_64_sync_handler+0xe4/0x158 el0t_64_sync+0x188/0x190 Fix it by making the start and end not only within the vma range, but also within the page table range. Link: https://lkml.kernel.org/r/20240612122822.4033433-1-wangkefeng.wang@xxxxxxxxxx Fixes: d2136d749d76 ("mm: support multi-size THP numa balancing") Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> Acked-by: David Hildenbrand <david@xxxxxxxxxx> Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> Cc: "Huang, Ying" <ying.huang@xxxxxxxxx> Cc: John Hubbard <jhubbard@xxxxxxxxxx> Cc: Liu Shixin <liushixin2@xxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Cc: Ryan Roberts <ryan.roberts@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memory.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) --- a/mm/memory.c~mm-fix-possible-oob-in-numa_rebuild_large_mapping +++ a/mm/memory.c @@ -5100,10 +5100,16 @@ static void numa_rebuild_large_mapping(s bool ignore_writable, bool pte_write_upgrade) { int nr = pte_pfn(fault_pte) - folio_pfn(folio); - unsigned long start = max(vmf->address - nr * PAGE_SIZE, vma->vm_start); - unsigned long end = min(vmf->address + (folio_nr_pages(folio) - nr) * PAGE_SIZE, vma->vm_end); - pte_t *start_ptep = vmf->pte - (vmf->address - start) / PAGE_SIZE; - unsigned long addr; + unsigned long start, end, addr = vmf->address; + unsigned long addr_start = addr - (nr << PAGE_SHIFT); + unsigned long pt_start = ALIGN_DOWN(addr, PMD_SIZE); + pte_t *start_ptep; + + /* Stay within the VMA and within the page table. */ + start = max3(addr_start, pt_start, vma->vm_start); + end = min3(addr_start + folio_size(folio), pt_start + PMD_SIZE, + vma->vm_end); + start_ptep = vmf->pte - ((addr - start) >> PAGE_SHIFT); /* Restore all PTEs' mapping of the large folio */ for (addr = start; addr != end; start_ptep++, addr += PAGE_SIZE) { _ Patches currently in -mm which might be from wangkefeng.wang@xxxxxxxxxx are mm-add-folio_alloc_mpol.patch mm-mempolicy-use-folio_alloc_mpol_noprof-in-vma_alloc_folio_noprof.patch mm-mempolicy-use-folio_alloc_mpol-in-alloc_migration_target_by_mpol.patch mm-shmem-use-folio_alloc_mpol-in-shmem_alloc_folio.patch mm-refactor-folio_undo_large_rmappable.patch mm-memcontrol-remove-page_memcg.patch rmap-remove-define_page_vma_walk.patch mm-migrate-simplify-__buffer_migrate_folio.patch mm-migrate_device-use-a-newfolio-in-__migrate_device_pages.patch mm-migrate_device-unify-migrate-folio-for-migrate_sync_no_copy.patch mm-migrate-remove-migrate_folio_extra.patch mm-remove-migrate_sync_no_copy-mode.patch fs-proc-task_mmu-use-folio-api-in-pte_is_pinned.patch mm-remove-page_maybe_dma_pinned.patch mm-remove-page_maybe_dma_pinned-fix.patch fb_defio-use-a-folio-in-fb_deferred_io_work.patch mm-remove-page_mkclean.patch mm-move-memory_failure_queue-into-copy_mc__highpage.patch mm-add-folio_mc_copy.patch mm-migrate-split-folio_migrate_mapping.patch mm-migrate-support-poisoned-recover-from-migrate-folio.patch fs-hugetlbfs-support-poison-recover-from-hugetlbfs_migrate_folio.patch mm-migrate-remove-folio_migrate_copy.patch