From: Nguyen Dinh Phi <phind.uet@gmail.com> stable inclusion from stable-v6.6.8 commit 1f75542ce7c4e958386fb4932185842c3c8e1c4d category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8ST59 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ 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> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- 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 b027be0b0b6f..590b038e449e 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; -- 2.20.1