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authorChristoph Hellwig <hch@lst.de>2019-07-12 06:57:25 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-12 21:05:45 +0300
commit817be129e6f254e5bd8c17b1da834c8f612dca28 (patch)
tree2797ca2c983365224a9d5f01c76b2e5caca8e7b1 /mm/gup.c
parent050a9adc64383aed3429a31432b4f5a7b0cdc8ac (diff)
downloadlinux-817be129e6f254e5bd8c17b1da834c8f612dca28.tar.xz
mm: validate get_user_pages_fast flags
We can only deal with FOLL_WRITE and/or FOLL_LONGTERM in get_user_pages_fast, so reject all other flags. Link: http://lkml.kernel.org/r/20190625143715.1689-14-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: James Hogan <jhogan@kernel.org> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/gup.c')
-rw-r--r--mm/gup.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/gup.c b/mm/gup.c
index cc5ddd8869b7..9d68cef2fa90 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2317,6 +2317,9 @@ 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;