[PATCH AUTOSEL 6.6 32/40] nfc: virtual_ncidev: Add variable to check if ndev is running

Sasha Levin
2023-11-28T21:13:21Z

From: Nguyen Dinh Phi <phind.uet@gmail.com>

[ Upstream commit 84d2db91f14a32dc856a5972e3f0907089093c7a ]

syzbot reported an memory leak that happens when an skb is add to
send_buff after virtual nci closed.
This patch adds a variable to track if the ndev is running before
handling new skb in send function.

Signed-off-by: Nguyen Dinh Phi <phind.uet@gmail.com>
Reported-by: syzbot+6eb09d75211863f15e3e@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/lkml/00000000000075472b06007df4fb@google.com
Reviewed-by: Bongsu Jeon
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/nfc/virtual_ncidev.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/nfc/virtual_ncidev.c b/drivers/nfc/virtual_ncidev.c
index b027be0b0b6ff..590b038e449e5 100644
--- a/drivers/nfc/virtual_ncidev.c
+++ b/drivers/nfc/virtual_ncidev.c
@@ -26,10 +26,14 @@ struct virtual_nci_dev {
struct mutex mtx;
struct sk_buff *send_buff;
struct wait_queue_head wq;
+ bool running;
};

static int virtual_nci_open(struct nci_dev *ndev)
{
+ struct virtual_nci_dev *vdev = nci_get_drvdata(ndev);
+
+ vdev->running = true;
return 0;
}

@@ -40,6 +44,7 @@ static int virtual_nci_close(struct nci_dev *ndev)
mutex_lock(&vdev->mtx);
kfree_skb(vdev->send_buff);
vdev->send_buff = NULL;
+ vdev->running = false;
mutex_unlock(&vdev->mtx);

return 0;
@@ -50,7 +55,7 @@ static int virtual_nci_send(struct nci_dev *ndev, struct sk_buff *skb)
struct virtual_nci_dev *vdev = nci_get_drvdata(ndev);

mutex_lock(&vdev->mtx);
- if (vdev->send_buff) {
+ if (vdev->send_buff || !vdev->running) {
mutex_unlock(&vdev->mtx);
kfree_skb(skb);
return -1;
--
2.42.0