CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's NFC (Near Field Communication) subsystem, specifically in the handling of concurrent calls to the nci_data_exchange_complete() function, which can lead to a double completion race condition. This flaw can result in a use-after-free condition, potentially causing system instability or crashes. Organizations utilizing Linux-based systems with NFC capabilities should prioritize addressing this vulnerability to mitigate risks associated with socket management and ensure system reliability.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: nfc: nci: fix double completion race in nci_data_exchange_complete nci_close_device() and nci_rx_work can both call nci_data_exchange_complete() concurrently. After commit 4527025d440ce8 ("nfc: nci: fix circular locking dependency in nci_close_device") moved flush_workqueue(ndev->rx_wq) after mutex_unlock(&ndev->req_lock), rx_work is no longer serialized with the explicit completion call in the close path. Both callers read the non-NULL callback pointer and invoke rawsock_data_exchange_complete(), which calls sock_put() -- but only one sock_hold() was taken, so the second sock_put() underflows the refcount and frees the socket while it is still in use. Replace the bare clear_bit(NCI_DATA_EXCHANGE) with test_and_clear_bit() so that only the first caller proceeds to invoke the callback.