From: Keith Busch <keith.busch@intel.com>
Date: Wed, 7 Nov 2018 14:37:45 +0000 (-0700)
Subject: block: Clear kernel memory before copying to user
X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=f3587d76da05f68098ddb1cb3c98cc6a9e8a402c;p=openwrt%2Fstaging%2Fblogic.git

block: Clear kernel memory before copying to user

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>
---

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);
 	}