From: Hugh Dickins Date: Tue, 11 Oct 2005 18:16:26 +0000 (+0100) Subject: [PATCH] Don't map the same page too much X-Git-Tag: v2.6.14-rc5~76 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=f5154a98a1931641f0448f6512294a15279110d7;p=linux-2.6-omap-h63xx.git [PATCH] Don't map the same page too much Refuse to install a page into a mapping if the mapping count is already ridiculously large. You probably cannot trigger this on 32-bit architectures, but on a 64-bit setup we should protect against it. Signed-off-by: Hugh Dickins Signed-off-by: Linus Torvalds --- diff --git a/mm/fremap.c b/mm/fremap.c index 3235fb77c13..ab23a0673c3 100644 --- a/mm/fremap.c +++ b/mm/fremap.c @@ -89,6 +89,9 @@ int install_page(struct mm_struct *mm, struct vm_area_struct *vma, size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; if (!page->mapping || page->index >= size) goto err_unlock; + err = -ENOMEM; + if (page_mapcount(page) > INT_MAX/2) + goto err_unlock; zap_pte(mm, vma, addr, pte);