[PATCH 13/16] mm: validate get_user_pages_fast flags
From: Christoph Hellwig <hch@lst.de>
Date: 2019-06-01 07:51:26
Also in:
linux-mips, linux-mm, linux-sh, lkml, sparclinux
Subsystem:
memory management, memory management - gup (get user pages), the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
We can only deal with FOLL_WRITE and/or FOLL_LONGTERM in get_user_pages_fast, so reject all other flags. Signed-off-by: Christoph Hellwig <hch@lst.de> --- mm/gup.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/mm/gup.c b/mm/gup.c
index c8da7764de9c..53b50c63ba51 100644
--- a/mm/gup.c
+++ b/mm/gup.c@@ -2316,6 +2316,9 @@ int get_user_pages_fast(unsigned long start, int nr_pages, unsigned long addr, len, end; int nr = 0, ret = 0; + if (WARN_ON_ONCE(gup_flags & ~(FOLL_WRITE | FOLL_LONGTERM))) + return -EINVAL; + start = untagged_addr(start) & PAGE_MASK; addr = start; len = (unsigned long) nr_pages << PAGE_SHIFT;
--
2.20.1