kernel.git/net/nfc, branch linux-5.10.y

nfc: nci: Fix race between rfkill and nci_unregister_device().

2026-02-06T15:40:11Z

[ Upstream commit d2492688bb9fed6ab6e313682c387ae71a66ebae ] syzbot reported the splat below [0] without a repro. It indicates that struct nci_dev.cmd_wq had been destroyed before nci_close_device() was called via rfkill. nci_dev.cmd_wq is only destroyed in nci_unregister_device(), which (I think) was called from virtual_ncidev_close() when syzbot close()d an fd of virtual_ncidev. The problem is that nci_unregister_device() destroys nci_dev.cmd_wq first and then calls nfc_unregister_device(), which removes the device from rfkill by rfkill_unregister(). So, the device is still visible via rfkill even after nci_dev.cmd_wq is destroyed. Let's unregister the device from rfkill first in nci_unregister_device(). Note that we cannot call nfc_unregister_device() before nci_close_device() because 1) nfc_unregister_device() calls device_del() which frees all memory allocated by devm_kzalloc() and linked to ndev->conn_info_list 2) nci_rx_work() could try to queue nci_conn_info to ndev->conn_info_list which could be leaked Thus, nfc_unregister_device() is split into two functions so we can remove rfkill interfaces only before nci_close_device(). [0]: DEBUG_LOCKS_WARN_ON(1) WARNING: kernel/locking/lockdep.c:238 at hlock_class kernel/locking/lockdep.c:238 [inline], CPU#0: syz.0.8675/6349 WARNING: kernel/locking/lockdep.c:238 at check_wait_context kernel/locking/lockdep.c:4854 [inline], CPU#0: syz.0.8675/6349 WARNING: kernel/locking/lockdep.c:238 at __lock_acquire+0x39d/0x2cf0 kernel/locking/lockdep.c:5187, CPU#0: syz.0.8675/6349 Modules linked in: CPU: 0 UID: 0 PID: 6349 Comm: syz.0.8675 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 RIP: 0010:hlock_class kernel/locking/lockdep.c:238 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4854 [inline] RIP: 0010:__lock_acquire+0x3a4/0x2cf0 kernel/locking/lockdep.c:5187 Code: 18 00 4c 8b 74 24 08 75 27 90 e8 17 f2 fc 02 85 c0 74 1c 83 3d 50 e0 4e 0e 00 75 13 48 8d 3d 43 f7 51 0e 48 c7 c6 8b 3a de 8d <67> 48 0f b9 3a 90 31 c0 0f b6 98 c4 00 00 00 41 8b 45 20 25 ff 1f RSP: 0018:ffffc9000c767680 EFLAGS: 00010046 RAX: 0000000000000001 RBX: 0000000000040000 RCX: 0000000000080000 RDX: ffffc90013080000 RSI: ffffffff8dde3a8b RDI: ffffffff8ff24ca0 RBP: 0000000000000003 R08: ffffffff8fef35a3 R09: 1ffffffff1fde6b4 R10: dffffc0000000000 R11: fffffbfff1fde6b5 R12: 00000000000012a2 R13: ffff888030338ba8 R14: ffff888030338000 R15: ffff888030338b30 FS: 00007fa5995f66c0(0000) GS:ffff8881256f8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7e72f842d0 CR3: 00000000485a0000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868 touch_wq_lockdep_map+0xcb/0x180 kernel/workqueue.c:3940 __flush_workqueue+0x14b/0x14f0 kernel/workqueue.c:3982 nci_close_device+0x302/0x630 net/nfc/nci/core.c:567 nci_dev_down+0x3b/0x50 net/nfc/nci/core.c:639 nfc_dev_down+0x152/0x290 net/nfc/core.c:161 nfc_rfkill_set_block+0x2d/0x100 net/nfc/core.c:179 rfkill_set_block+0x1d2/0x440 net/rfkill/core.c:346 rfkill_fop_write+0x461/0x5a0 net/rfkill/core.c:1301 vfs_write+0x29a/0xb90 fs/read_write.c:684 ksys_write+0x150/0x270 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa59b39acb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa5995f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fa59b615fa0 RCX: 00007fa59b39acb9 RDX: 0000000000000008 RSI: 0000200000000080 RDI: 0000000000000007 RBP: 00007fa59b408bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa59b616038 R14: 00007fa59b615fa0 R15: 00007ffc82218788 Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation") Reported-by: syzbot+f9c5fd1a0874f9069dce@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/695e7f56.050a0220.1c677c.036c.GAE@google.com/ Signed-off-by: Kuniyuki Iwashima Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260127040411.494931-1-kuniyu@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

nfc: llcp: Fix memleak in nfc_llcp_send_ui_frame().

2026-02-06T15:40:10Z

[ Upstream commit 165c34fb6068ff153e3fc99a932a80a9d5755709 ] syzbot reported various memory leaks related to NFC, struct nfc_llcp_sock, sk_buff, nfc_dev, etc. [0] The leading log hinted that nfc_llcp_send_ui_frame() failed to allocate skb due to sock_error(sk) being -ENXIO. ENXIO is set by nfc_llcp_socket_release() when struct nfc_llcp_local is destroyed by local_cleanup(). The problem is that there is no synchronisation between nfc_llcp_send_ui_frame() and local_cleanup(), and skb could be put into local->tx_queue after it was purged in local_cleanup(): CPU1 CPU2 ---- ---- nfc_llcp_send_ui_frame() local_cleanup() |- do { ' |- pdu = nfc_alloc_send_skb(..., &err) | . | |- nfc_llcp_socket_release(local, false, ENXIO); | |- skb_queue_purge(&local->tx_queue); | | ' | |- skb_queue_tail(&local->tx_queue, pdu); | ... | |- pdu = nfc_alloc_send_skb(..., &err) | ^._________________________________.' local_cleanup() is called for struct nfc_llcp_local only after nfc_llcp_remove_local() unlinks it from llcp_devices. If we hold local->tx_queue.lock then, we can synchronise the thread and nfc_llcp_send_ui_frame(). Let's do that and check list_empty(&local->list) before queuing skb to local->tx_queue in nfc_llcp_send_ui_frame(). [0]: [ 56.074943][ T6096] llcp: nfc_llcp_send_ui_frame: Could not allocate PDU (error=-6) [ 64.318868][ T5813] kmemleak: 6 new suspected memory leaks (see /sys/kernel/debug/kmemleak) BUG: memory leak unreferenced object 0xffff8881272f6800 (size 1024): comm "syz.0.17", pid 6096, jiffies 4294942766 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 27 00 03 40 00 00 00 00 00 00 00 00 00 00 00 00 '..@............ backtrace (crc da58d84d): kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline] slab_post_alloc_hook mm/slub.c:4979 [inline] slab_alloc_node mm/slub.c:5284 [inline] __do_kmalloc_node mm/slub.c:5645 [inline] __kmalloc_noprof+0x3e3/0x6b0 mm/slub.c:5658 kmalloc_noprof include/linux/slab.h:961 [inline] sk_prot_alloc+0x11a/0x1b0 net/core/sock.c:2239 sk_alloc+0x36/0x360 net/core/sock.c:2295 nfc_llcp_sock_alloc+0x37/0x130 net/nfc/llcp_sock.c:979 llcp_sock_create+0x71/0xd0 net/nfc/llcp_sock.c:1044 nfc_sock_create+0xc9/0xf0 net/nfc/af_nfc.c:31 __sock_create+0x1a9/0x340 net/socket.c:1605 sock_create net/socket.c:1663 [inline] __sys_socket_create net/socket.c:1700 [inline] __sys_socket+0xb9/0x1a0 net/socket.c:1747 __do_sys_socket net/socket.c:1761 [inline] __se_sys_socket net/socket.c:1759 [inline] __x64_sys_socket+0x1b/0x30 net/socket.c:1759 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xa4/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f BUG: memory leak unreferenced object 0xffff88810fbd9800 (size 240): comm "syz.0.17", pid 6096, jiffies 4294942850 hex dump (first 32 bytes): 68 f0 ff 08 81 88 ff ff 68 f0 ff 08 81 88 ff ff h.......h....... 00 00 00 00 00 00 00 00 00 68 2f 27 81 88 ff ff .........h/'.... backtrace (crc 6cc652b1): kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline] slab_post_alloc_hook mm/slub.c:4979 [inline] slab_alloc_node mm/slub.c:5284 [inline] kmem_cache_alloc_node_noprof+0x36f/0x5e0 mm/slub.c:5336 __alloc_skb+0x203/0x240 net/core/skbuff.c:660 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0x69/0x3f0 net/core/skbuff.c:6671 sock_alloc_send_pskb+0x379/0x3e0 net/core/sock.c:2965 sock_alloc_send_skb include/net/sock.h:1859 [inline] nfc_alloc_send_skb+0x45/0x80 net/nfc/core.c:724 nfc_llcp_send_ui_frame+0x162/0x360 net/nfc/llcp_commands.c:766 llcp_sock_sendmsg+0x14c/0x1d0 net/nfc/llcp_sock.c:814 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] __sys_sendto+0x2d8/0x2f0 net/socket.c:2244 __do_sys_sendto net/socket.c:2251 [inline] __se_sys_sendto net/socket.c:2247 [inline] __x64_sys_sendto+0x28/0x30 net/socket.c:2247 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xa4/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: 94f418a20664 ("NFC: UI frame sending routine implementation") Reported-by: syzbot+f2d245f1d76bbfa50e4c@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/697569c7.a00a0220.33ccc7.0014.GAE@google.com/T/#u Signed-off-by: Kuniyuki Iwashima Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260125010214.1572439-1-kuniyu@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: nfc: fix deadlock between nfc_unregister_device and rfkill_fop_write

2026-01-19T12:11:59Z

commit 1ab526d97a57e44d26fadcc0e9adeb9c0c0182f5 upstream. A deadlock can occur between nfc_unregister_device() and rfkill_fop_write() due to lock ordering inversion between device_lock and rfkill_global_mutex. The problematic lock order is: Thread A (rfkill_fop_write): rfkill_fop_write() mutex_lock(&rfkill_global_mutex) rfkill_set_block() nfc_rfkill_set_block() nfc_dev_down() device_lock(&dev->dev) <- waits for device_lock Thread B (nfc_unregister_device): nfc_unregister_device() device_lock(&dev->dev) rfkill_unregister() mutex_lock(&rfkill_global_mutex) <- waits for rfkill_global_mutex This creates a classic ABBA deadlock scenario. Fix this by moving rfkill_unregister() and rfkill_destroy() outside the device_lock critical section. Store the rfkill pointer in a local variable before releasing the lock, then call rfkill_unregister() after releasing device_lock. This change is safe because rfkill_fop_write() holds rfkill_global_mutex while calling the rfkill callbacks, and rfkill_unregister() also acquires rfkill_global_mutex before cleanup. Therefore, rfkill_unregister() will wait for any ongoing callback to complete before proceeding, and device_del() is only called after rfkill_unregister() returns, preventing any use-after-free. The similar lock ordering in nfc_register_device() (device_lock -> rfkill_global_mutex via rfkill_register) is safe because during registration the device is not yet in rfkill_list, so no concurrent rfkill operations can occur on this device. Fixes: 3e3b5dfcd16a ("NFC: reorder the logic in nfc_{un,}register_device") Cc: stable@vger.kernel.org Reported-by: syzbot+4ef89409a235d804c6c2@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=4ef89409a235d804c6c2 Link: https://lore.kernel.org/all/20251217054908.178907-1-kartikey406@gmail.com/T/ [v1] Signed-off-by: Deepanshu Kartikey Reviewed-by: Krzysztof Kozlowski Link: https://patch.msgid.link/20251218012355.279940-1-kartikey406@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

NFC: nci: uart: Set tty->disc_data only in success path

2025-06-27T10:04:13Z

commit fc27ab48904ceb7e4792f0c400f1ef175edf16fe upstream. Setting tty->disc_data before opening the NCI device means we need to clean it up on error paths. This also opens some short window if device starts sending data, even before NCIUARTSETDRIVER IOCTL succeeded (broken hardware?). Close the window by exposing tty->disc_data only on the success path, when opening of the NCI device and try_module_get() succeeds. The code differs in error path in one aspect: tty->disc_data won't be ever assigned thus NULL-ified. This however should not be relevant difference, because of "tty->disc_data=NULL" in nci_uart_tty_open(). Cc: Linus Torvalds Fixes: 9961127d4bce ("NFC: nci: add generic uart support") Cc: Signed-off-by: Krzysztof Kozlowski Reviewed-by: Greg Kroah-Hartman Link: https://patch.msgid.link/20250618073649.25049-2-krzysztof.kozlowski@linaro.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

NFC: nci: Add bounds checking in nci_hci_create_pipe()

2025-03-13T11:47:12Z

commit 110b43ef05342d5a11284cc8b21582b698b4ef1c upstream. The "pipe" variable is a u8 which comes from the network. If it's more than 127, then it results in memory corruption in the caller, nci_hci_connect_gate(). Cc: stable@vger.kernel.org Fixes: a1b0b9415817 ("NFC: nci: Create pipe on specific gate in nci_hci_connect_gate") Signed-off-by: Dan Carpenter Reviewed-by: Simon Horman Reviewed-by: Krzysztof Kozlowski Link: https://patch.msgid.link/bcf5453b-7204-4297-9c20-4d8c7dacf586@stanley.mountain Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

nfc: nci: Fix handling of zero-length payload packets in nci_rx_work()

2024-06-16T11:32:27Z

[ Upstream commit 6671e352497ca4bb07a96c48e03907065ff77d8a ] When nci_rx_work() receives a zero-length payload packet, it should not discard the packet and exit the loop. Instead, it should continue processing subsequent packets. Fixes: d24b03535e5e ("nfc: nci: Fix uninit-value in nci_dev_up and nci_ntf_packet") Signed-off-by: Ryosuke Yasuoka Reviewed-by: Simon Horman Reviewed-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20240521153444.535399-1-ryasuoka@redhat.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

nfc: nci: Fix kcov check in nci_rx_work()

2024-06-16T11:32:27Z

[ Upstream commit 19e35f24750ddf860c51e51c68cf07ea181b4881 ] Commit 7e8cdc97148c ("nfc: Add KCOV annotations") added kcov_remote_start_common()/kcov_remote_stop() pair into nci_rx_work(), with an assumption that kcov_remote_stop() is called upon continue of the for loop. But commit d24b03535e5e ("nfc: nci: Fix uninit-value in nci_dev_up and nci_ntf_packet") forgot to call kcov_remote_stop() before break of the for loop. Reported-by: syzbot Closes: https://syzkaller.appspot.com/bug?extid=0438378d6f157baae1a2 Fixes: d24b03535e5e ("nfc: nci: Fix uninit-value in nci_dev_up and nci_ntf_packet") Suggested-by: Andrey Konovalov Signed-off-by: Tetsuo Handa Reviewed-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/6d10f829-5a0c-405a-b39a-d7266f3a1a0b@I-love.SAKURA.ne.jp Signed-off-by: Jakub Kicinski Stable-dep-of: 6671e352497c ("nfc: nci: Fix handling of zero-length payload packets in nci_rx_work()") Signed-off-by: Sasha Levin

nfc: nci: Fix uninit-value in nci_rx_work

2024-06-16T11:32:26Z

[ Upstream commit e4a87abf588536d1cdfb128595e6e680af5cf3ed ] syzbot reported the following uninit-value access issue [1] nci_rx_work() parses received packet from ndev->rx_q. It should be validated header size, payload size and total packet size before processing the packet. If an invalid packet is detected, it should be silently discarded. Fixes: d24b03535e5e ("nfc: nci: Fix uninit-value in nci_dev_up and nci_ntf_packet") Reported-and-tested-by: syzbot+d7b4dc6cd50410152534@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=d7b4dc6cd50410152534 [1] Signed-off-by: Ryosuke Yasuoka Reviewed-by: Krzysztof Kozlowski Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

nfc: nci: Fix uninit-value in nci_dev_up and nci_ntf_packet

2024-04-13T10:59:14Z

[ Upstream commit d24b03535e5eb82e025219c2f632b485409c898f ] syzbot reported the following uninit-value access issue [1][2]: nci_rx_work() parses and processes received packet. When the payload length is zero, each message type handler reads uninitialized payload and KMSAN detects this issue. The receipt of a packet with a zero-size payload is considered unexpected, and therefore, such packets should be silently discarded. This patch resolved this issue by checking payload size before calling each message type handler codes. Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation") Reported-and-tested-by: syzbot+7ea9413ea6749baf5574@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+29b5ca705d2e0f4a44d2@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=7ea9413ea6749baf5574 [1] Closes: https://syzkaller.appspot.com/bug?extid=29b5ca705d2e0f4a44d2 [2] Signed-off-by: Ryosuke Yasuoka Reviewed-by: Jeremy Cline Reviewed-by: Krzysztof Kozlowski Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

nfc: nci: free rx_data_reassembly skb on NCI device cleanup

2024-02-23T07:42:26Z

commit bfb007aebe6bff451f7f3a4be19f4f286d0d5d9c upstream. rx_data_reassembly skb is stored during NCI data exchange for processing fragmented packets. It is dropped only when the last fragment is processed or when an NTF packet with NCI_OP_RF_DEACTIVATE_NTF opcode is received. However, the NCI device may be deallocated before that which leads to skb leak. As by design the rx_data_reassembly skb is bound to the NCI device and nothing prevents the device to be freed before the skb is processed in some way and cleaned, free it on the NCI device cleanup. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation") Cc: stable@vger.kernel.org Reported-by: syzbot+6b7c68d9c21e4ee4251b@syzkaller.appspotmail.com Closes: https://lore.kernel.org/lkml/000000000000f43987060043da7b@google.com/ Signed-off-by: Fedor Pchelkin Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman