[PATCH net 3/5] nfc: nci: complete pending data exchange on device close

[Jakub Kicinski <kuba@kernel.org>]

In nci_close_device(), complete any pending data exchange before
closing. The data exchange callback (e.g.
rawsock_data_exchange_complete) holds a socket reference.

NIPA occasionally hits this leak:

unreferenced object 0xff1100000f435000 (size 2048):
  comm "nci_dev", pid 3954, jiffies 4295441245
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    27 00 01 40 00 00 00 00 00 00 00 00 00 00 00 00  '..@............
  backtrace (crc ec2b3c5):
    __kmalloc_noprof+0x4db/0x730
    sk_prot_alloc.isra.0+0xe4/0x1d0
    sk_alloc+0x36/0x760
    rawsock_create+0xd1/0x540
    nfc_sock_create+0x11f/0x280
    __sock_create+0x22d/0x630
    __sys_socket+0x115/0x1d0
    __x64_sys_socket+0x72/0xd0
    do_syscall_64+0x117/0xfc0
    entry_SYSCALL_64_after_hwframe+0x4b/0x53

Fixes: 38f04c6b1b68 ("NFC: protect nci_data_exchange transactions")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 net/nfc/nci/core.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 40fc397858ce..f8c0bab2ec07 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -567,6 +567,10 @@ static int nci_close_device(struct nci_dev *ndev)
 		flush_workqueue(ndev->cmd_wq);
 		timer_delete_sync(&ndev->cmd_timer);
 		timer_delete_sync(&ndev->data_timer);
+		if (test_bit(NCI_DATA_EXCHANGE, &ndev->flags))
+			nci_data_exchange_complete(ndev, NULL,
+						   ndev->cur_conn_id,
+						   -ENODEV);
 		mutex_unlock(&ndev->req_lock);
 		return 0;
 	}
@@ -598,6 +602,11 @@ static int nci_close_device(struct nci_dev *ndev)
 	flush_workqueue(ndev->cmd_wq);
 
 	timer_delete_sync(&ndev->cmd_timer);
+	timer_delete_sync(&ndev->data_timer);
+
+	if (test_bit(NCI_DATA_EXCHANGE, &ndev->flags))
+		nci_data_exchange_complete(ndev, NULL, ndev->cur_conn_id,
+					   -ENODEV);
 
 	/* Clear flags except NCI_UNREG */
 	ndev->flags &= BIT(NCI_UNREG);
-- 
2.53.0