From: Jérôme Glisse <jglisse@redhat.com>
Date: Wed, 10 Apr 2019 20:27:51 +0000 (-0400)
Subject: block: do not leak memory in bio_copy_user_iov()
X-Git-Tag: v4.14.112~21
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6ec54fc43b5a43c6b456b04843f13a2dded1c4f2;p=thirdparty%2Fkernel%2Fstable.git

block: do not leak memory in bio_copy_user_iov()

commit a3761c3c91209b58b6f33bf69dd8bb8ec0c9d925 upstream.

When bio_add_pc_page() fails in bio_copy_user_iov() we should free
the page we just allocated otherwise we are leaking it.

Cc: linux-block@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@vger.kernel.org
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/block/bio.c b/block/bio.c
index 2e5d881423b82..d01ab919b3139 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1280,8 +1280,11 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
 			}
 		}
 
-		if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes)
+		if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) {
+			if (!map_data)
+				__free_page(page);
 			break;
+		}
 
 		len -= bytes;
 		offset = 0;