Don't feed anything but regular iovec's to blk_rq_map_user_iov

commit a0ac402cfcdc904f9772e1762b3fda112dcc56a0 upstream.

In theory we could map other things, but there's a reason that function
is called "user_iov".  Using anything else (like splice can do) just
confuses it.

Reported-and-tested-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/block/blk-map.c b/block/blk-map.c
index f565e11f465aa145120973bce58ef7ecc192f349..69953bd97e6597f684803b5064662a13abb8c65b 100644 (file)
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -90,6 +90,9 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
        if (!iter || !iter->count)
                return -EINVAL;
 
+       if (!iter_is_iovec(iter))
+               return -EINVAL;
+
        iov_for_each(iov, i, *iter) {
                unsigned long uaddr = (unsigned long) iov.iov_base;