CVE-2026-31509

Description

In the Linux kernel, the following vulnerability has been resolved: nfc: nci: fix circular locking dependency in nci_close_device nci_close_device() flushes rx_wq and tx_wq while holding req_lock. This causes a circular locking dependency because nci_rx_work() running on rx_wq can end up taking req_lock too: nci_rx_work -> nci_rx_data_packet -> nci_data_exchange_complete -> __sk_destruct -> rawsock_destruct -> nfc_deactivate_target -> nci_deactivate_target -> nci_request -> mutex_lock(&ndev->req_lock) Move the flush of rx_wq after req_lock has been released. This should safe (I think) because NCI_UP has already been cleared and the transport is closed, so the work will see it and return -ENETDOWN. NIPA has been hitting this running the nci selftest with a debug kernel on roughly 4% of the runs.

References

• https://git.kernel.org/stable/c/09143c0e8f3b03517e6233aad42f45c794d8df8e
• https://git.kernel.org/stable/c/1edc12d2bbcb7a8d0f1088e6fccb9d8c01bb1289
• https://git.kernel.org/stable/c/4527025d440ce84bf56e75ce1df2e84cb8178616
• https://git.kernel.org/stable/c/5eef9ebec7f5738f12cadede3545c05b34bf5ac3
• https://git.kernel.org/stable/c/7ed00a3edc8597fe2333f524401e2889aa1b5edf