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From:   Soenke Huster <soenke.huster@eknoes.de>
To:     Marcel Holtmann <marcel@holtmann.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc:     Soenke Huster <soenke.huster@eknoes.de>,
        linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH Resend] Bluetooth: virtio_bt: Use skb_put to set length
Date:   Mon, 25 Jul 2022 08:53:15 +0200
Message-Id: <20220725065316.6942-1-soenke.huster@eknoes.de>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

By using skb_put we ensure that skb->tail is set
correctly. Currently, skb->tail is always zero, which
leads to errors, such as the following page fault in
rfcomm_recv_frame:

    BUG: unable to handle page fault for address: ffffed1021de29ff
    #PF: supervisor read access in kernel mode
    #PF: error_code(0x0000) - not-present page
    RIP: 0010:rfcomm_run+0x831/0x4040 (net/bluetooth/rfcomm/core.c:1751)

Signed-off-by: Soenke Huster <soenke.huster@eknoes.de>
---
 drivers/bluetooth/virtio_bt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/bluetooth/virtio_bt.c b/drivers/bluetooth/virtio_bt.c
index 67c21263f9e0..fd281d439505 100644
--- a/drivers/bluetooth/virtio_bt.c
+++ b/drivers/bluetooth/virtio_bt.c
@@ -219,7 +219,7 @@ static void virtbt_rx_work(struct work_struct *work)
 	if (!skb)
 		return;
 
-	skb->len = len;
+	skb_put(skb, len);
 	virtbt_rx_handle(vbt, skb);
 
 	if (virtbt_add_inbuf(vbt) < 0)
-- 
2.36.1