Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Sat,  1 Apr 2023 06:05:09 +0000
In-Reply-To: <20230401060509.3608259-1-dhavale@google.com>
Mime-Version: 1.0
References: <20230401060509.3608259-1-dhavale@google.com>
Message-ID: <20230401060509.3608259-3-dhavale@google.com>
Subject: [PATCH v1 2/2] usb: gadgetfs: Fix ep_read_iter to handle ITER_UBUF
From:   Sandeep Dhavale <dhavale@google.com>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Keith Busch <kbusch@kernel.org>, Jens Axboe <axboe@kernel.dk>
Cc:     Sandeep Dhavale <dhavale@google.com>, kernel-team@android.com,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

iov_iter for ep_read_iter can be ITER_UBUF with io_uring.
In that case dup_iter() does not have to allocate iov and it can
return NULL. Fix the assumption by checking for iter_is_ubuf()
other wise ep_read_iter can treat this as failure and return -ENOMEM.

Fixes: 1e23db450cff ("io_uring: use iter_ubuf for single range imports")
Signed-off-by: Sandeep Dhavale <dhavale@google.com>
---
 drivers/usb/gadget/legacy/inode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
index d605bc2e7e8f..28249d0bf062 100644
--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -614,7 +614,7 @@ ep_read_iter(struct kiocb *iocb, struct iov_iter *to)
 		if (!priv)
 			goto fail;
 		priv->to_free = dup_iter(&priv->to, to, GFP_KERNEL);
-		if (!priv->to_free) {
+		if (!iter_is_ubuf(&priv->to) && !priv->to_free) {
 			kfree(priv);
 			goto fail;
 		}
-- 
2.40.0.348.gf938b09366-goog