From 1cfd0ddd82232804e03f3023f6a58b50dfef0574 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 24 Sep 2017 10:21:15 -0400 Subject: [PATCH] bio_copy_user_iov(): don't ignore ->iov_offset Since "block: support large requests in blk_rq_map_user_iov" we started to call it with partially drained iter; that works fine on the write side, but reads create a copy of iter for completion time. And that needs to take the possibility of ->iov_iter != 0 into account... Cc: stable@vger.kernel.org #v4.5+ Signed-off-by: Al Viro --- block/bio.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/bio.c b/block/bio.c index 9e9606d26cc6..101c2a9b5481 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1239,8 +1239,8 @@ struct bio *bio_copy_user_iov(struct request_queue *q, */ bmd->is_our_pages = map_data ? 0 : 1; memcpy(bmd->iov, iter->iov, sizeof(struct iovec) * iter->nr_segs); - iov_iter_init(&bmd->iter, iter->type, bmd->iov, - iter->nr_segs, iter->count); + bmd->iter = *iter; + bmd->iter.iov = bmd->iov; ret = -ENOMEM; bio = bio_kmalloc(gfp_mask, nr_pages);