kernel/linux.git/net/nfc, branch v7.1-rc6

nfc: hci: fix out-of-bounds read in HCP header parsing

2026-05-07T10:42:09+00:00

Both nfc_hci_recv_from_llc() and nci_hci_data_received_cb() read packet->header from skb->data at function entry without first checking that the buffer holds at least one byte. A malicious NFC peer can send a 0-byte HCP frame that passes through the SHDLC layer and reaches these functions, causing an out-of-bounds heap read of packet->header. The same 0-byte frame, if queued as a non-final fragment, also causes the reassembly loop to underflow msg_len to UINT_MAX, triggering skb_over_panic() when the reassembled skb is written. Fix this by adding a pskb_may_pull() check at the entry of each function before packet->header is first accessed. The existing pskb_may_pull() checks before the reassembled hcp_skb is cast to struct hcp_packet remain in place to guard the 2-byte HCP message header. Fixes: 8b8d2e08bf0d ("NFC: HCI support") Fixes: 11f54f228643 ("NFC: nci: Add HCI over NCI protocol support") Cc: stable@vger.kernel.org Reviewed-by: Simon Horman Signed-off-by: Ashutosh Desai Link: https://patch.msgid.link/20260505170712.96560-1-ashutoshdesai993@gmail.com Signed-off-by: David Heidelberg

nfc: llcp: Fix use-after-free race in nfc_llcp_recv_cc()

2026-05-05T09:37:11+00:00

A race condition exists in the NFC LLCP connection state machine where the connection acceptance packet (CC) can be processed concurrently with socket release. This can lead to a use-after-free of the socket object. When nfc_llcp_recv_cc() moves the socket from the connecting_sockets list to the sockets list, it does so without holding the socket lock. If llcp_sock_release() is executing concurrently, it might have already unlinked the socket and dropped its references, which can result in nfc_llcp_recv_cc() linking a freed socket into the live list. Fix this by holding lock_sock() during the state transition and list movement in nfc_llcp_recv_cc(). After acquiring the lock, check if the socket is still hashed to ensure it hasn't already been unlinked and marked for destruction by the release path. This aligns the locking pattern with recv_hdlc() and recv_disc(). Fixes: a69f32af86e3 ("NFC: Socket linked list") Signed-off-by: Lee Jones Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260429134115.3558604-2-lee@kernel.org Signed-off-by: David Heidelberg

nfc: llcp: Fix use-after-free in llcp_sock_release()

2026-05-05T09:37:10+00:00

llcp_sock_release() unconditionally unlinks the socket from the local sockets list. However, if the socket is still in connecting state, it is on the connecting list. Fix this by checking the socket state and unlinking from the correct list. Fixes: b4011239a08e ("NFC: llcp: Fix non blocking sockets connections") Signed-off-by: Lee Jones Link: https://patch.msgid.link/20260429134115.3558604-1-lee@kernel.org Signed-off-by: David Heidelberg

NFC: digital: Bounds check NFC-A cascade depth in SDD response handler

2026-04-12T18:40:45+00:00

The NFC-A anti-collision cascade in digital_in_recv_sdd_res() appends 3 or 4 bytes to target->nfcid1 on each round, but the number of cascade rounds is controlled entirely by the peer device. The peer sets the cascade tag in the SDD_RES (deciding 3 vs 4 bytes) and the cascade-incomplete bit in the SEL_RES (deciding whether another round follows). ISO 14443-3 limits NFC-A to three cascade levels and target->nfcid1 is sized accordingly (NFC_NFCID1_MAXSIZE = 10), but nothing in the driver actually enforces this. This means a malicious peer can keep the cascade running, writing past the heap-allocated nfc_target with each round. Fix this by rejecting the response when the accumulated UID would exceed the buffer. Commit e329e71013c9 ("NFC: nci: Bounds check struct nfc_target arrays") fixed similar missing checks against the same field on the NCI path. Cc: Simon Horman Cc: Kees Cook Cc: Thierry Escande Cc: Samuel Ortiz Fixes: 2c66daecc409 ("NFC Digital: Add NFC-A technology support") Cc: stable Assisted-by: gregkh_clanker_t1000 Signed-off-by: Greg Kroah-Hartman Link: https://patch.msgid.link/2026040913-figure-seducing-bd3f@gregkh Signed-off-by: Jakub Kicinski

nfc: llcp: add missing return after LLCP_CLOSED checks

2026-04-12T18:12:44+00:00

In nfc_llcp_recv_hdlc() and nfc_llcp_recv_disc(), when the socket state is LLCP_CLOSED, the code correctly calls release_sock() and nfc_llcp_sock_put() but fails to return. Execution falls through to the remainder of the function, which calls release_sock() and nfc_llcp_sock_put() again. This results in a double release_sock() and a refcount underflow via double nfc_llcp_sock_put(), leading to a use-after-free. Add the missing return statements after the LLCP_CLOSED branches in both functions to prevent the fall-through. Fixes: d646960f7986 ("NFC: Initial LLCP support") Signed-off-by: Junxi Qian Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260408081006.3723-1-qjx1298677004@gmail.com Signed-off-by: Jakub Kicinski

nfc: nci: fix circular locking dependency in nci_close_device

2026-03-19T23:56:18+00:00

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. Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation") Reviewed-by: Ian Ray Link: https://patch.msgid.link/20260317193334.988609-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

nfc: rawsock: cancel tx_work before socket teardown

2026-03-05T02:18:57+00:00

In rawsock_release(), cancel any pending tx_work and purge the write queue before orphaning the socket. rawsock_tx_work runs on the system workqueue and calls nfc_data_exchange which dereferences the NCI device. Without synchronization, tx_work can race with socket and device teardown when a process is killed (e.g. by SIGKILL), leading to use-after-free or leaked references. Set SEND_SHUTDOWN first so that if tx_work is already running it will see the flag and skip transmitting, then use cancel_work_sync to wait for any in-progress execution to finish, and finally purge any remaining queued skbs. Fixes: 23b7869c0fd0 ("NFC: add the NFC socket raw protocol") Reviewed-by: Joe Damato Link: https://patch.msgid.link/20260303162346.2071888-6-kuba@kernel.org Signed-off-by: Jakub Kicinski

nfc: nci: clear NCI_DATA_EXCHANGE before calling completion callback

2026-03-05T02:18:57+00:00

Move clear_bit(NCI_DATA_EXCHANGE) before invoking the data exchange callback in nci_data_exchange_complete(). The callback (e.g. rawsock_data_exchange_complete) may immediately schedule another data exchange via schedule_work(tx_work). On a multi-CPU system, tx_work can run and reach nci_transceive() before the current nci_data_exchange_complete() clears the flag, causing test_and_set_bit(NCI_DATA_EXCHANGE) to return -EBUSY and the new transfer to fail. This causes intermittent flakes in nci/nci_dev in NIPA: # # RUN NCI.NCI1_0.t4t_tag_read ... # # t4t_tag_read: Test terminated by timeout # # FAIL NCI.NCI1_0.t4t_tag_read # not ok 3 NCI.NCI1_0.t4t_tag_read Fixes: 38f04c6b1b68 ("NFC: protect nci_data_exchange transactions") Reviewed-by: Joe Damato Link: https://patch.msgid.link/20260303162346.2071888-5-kuba@kernel.org Signed-off-by: Jakub Kicinski

nfc: nci: complete pending data exchange on device close

2026-03-05T02:18:57+00:00

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") Reviewed-by: Joe Damato Link: https://patch.msgid.link/20260303162346.2071888-4-kuba@kernel.org Signed-off-by: Jakub Kicinski

nfc: digital: free skb on digital_in_send error paths

2026-03-05T02:16:10+00:00

digital_in_send() takes ownership of the skb passed by the caller (nfc_data_exchange), make sure it's freed on all error paths. Found looking around the real driver for similar bugs to the one just fixed in nci. Fixes: 2c66daecc409 ("NFC Digital: Add NFC-A technology support") Reviewed-by: Joe Damato Link: https://patch.msgid.link/20260303162346.2071888-3-kuba@kernel.org Signed-off-by: Jakub Kicinski