From: Keith Busch <keith.busch@intel.com>
Date: Wed, 7 Nov 2018 07:37:45 -0700
Subject: [PATCH] block: Clear kernel memory before copying to user
Git-commit: f3587d76da05f68098ddb1cb3c98cc6a9e8a402c
Patch-mainline: v4.20-rc2
References: bsc#1104967,FATE#325924

If the kernel allocates a bounce buffer for user read data, this memory
needs to be cleared before copying it to the user, otherwise it may leak
kernel memory to user space.

Laurence Oberman <loberman@redhat.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 block/bio.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/block/bio.c b/block/bio.c
index 4a5a036268fb..9a9c59067521 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1260,6 +1260,7 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
 		if (ret)
 			goto cleanup;
 	} else {
+		zero_fill_bio(bio);
 		iov_iter_advance(iter, bio->bi_iter.bi_size);
 	}
 
-- 
2.16.4