On Sun, Dec 09, 2018 at 07:08:14PM -0800, Bart Van Assche wrote:
> According to what I found in
> https://bugzilla.kernel.org/show_bug.cgi?id=201935 patch "block: Clear
> kernel memory before copying to user" broke tape access. Hence revert
> that patch.
Instead of reverting back to the leaking arbitrary kernel memory, why
not just make a fix on top of it? This should do it:
---
diff --git a/block/bio.c b/block/bio.c
index c4ef8aa46452..55a5386fd431 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1262,7 +1262,8 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
if (ret)
goto cleanup;
} else {
- zero_fill_bio(bio);
+ if (bmd->is_our_pages)
+ zero_fill_bio(bio);
iov_iter_advance(iter, bio->bi_iter.bi_size);
}
--
