[PATCH 5.0 079/117] block: do not leak memory in bio_copy_user_iov()

Greg Kroah-Hartman
2019-04-15T19:13:14Z

From: Jérôme Glisse <jglisse@redhat.com>

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>

---
block/bio.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/block/bio.c
+++ b/block/bio.c
@@ -1238,8 +1238,11 @@ struct bio *bio_copy_user_iov(struct req
}
}

- 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;