The patch titled mremap: check for overflow using deltas has been added to the -mm tree. Its filename is mremap-check-for-overflow-using-deltas.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: mremap: check for overflow using deltas From: Andrea Arcangeli <aarcange@xxxxxxxxxx> Using "- 1" relies on the old_end to be page aligned and PAGE_SIZE > 1, those are reasonable requirements but the check remains obscure and it looks more like an off by one error than an overflow check. This I feel will improve readability. Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx> Acked-by: Johannes Weiner <jweiner@xxxxxxxxxx> Acked-by: Mel Gorman <mgorman@xxxxxxx> Acked-by: Rik van Riel <riel@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/mremap.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff -puN mm/mremap.c~mremap-check-for-overflow-using-deltas mm/mremap.c --- a/mm/mremap.c~mremap-check-for-overflow-using-deltas +++ a/mm/mremap.c @@ -141,9 +141,10 @@ unsigned long move_page_tables(struct vm for (; old_addr < old_end; old_addr += extent, new_addr += extent) { cond_resched(); next = (old_addr + PMD_SIZE) & PMD_MASK; - if (next - 1 > old_end) - next = old_end; + /* even if next overflowed, extent below will be ok */ extent = next - old_addr; + if (extent > old_end - old_addr) + extent = old_end - old_addr; old_pmd = get_old_pmd(vma->vm_mm, old_addr); if (!old_pmd) continue; _ Patches currently in -mm which might be from aarcange@xxxxxxxxxx are mm-compaction-trivial-clean-up-in-acct_isolated.patch mm-change-isolate-mode-from-define-to-bitwise-type.patch mm-compaction-make-isolate_lru_page-filter-aware.patch mm-zone_reclaim-make-isolate_lru_page-filter-aware.patch mm-migration-clean-up-unmap_and_move.patch mremap-check-for-overflow-using-deltas.patch mremap-avoid-sending-one-ipi-per-page.patch thp-mremap-support-and-tlb-optimization.patch thp-mremap-support-and-tlb-optimization-fix.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html