linux-toradex.git/net/nfc, branch v6.19

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

2026-01-29T03:32:26+00:00

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

nfc: llcp: Fix memleak in nfc_llcp_send_ui_frame().

2026-01-27T03:51:46+00:00

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

net: nfc: fix deadlock between nfc_unregister_device and rfkill_fop_write

2025-12-28T08:15:42+00:00

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

net: Convert proto_ops connect() callbacks to use sockaddr_unsized

2025-11-05T03:10:32+00:00

Update all struct proto_ops connect() callback function prototypes from
"struct sockaddr *" to "struct sockaddr_unsized *" to avoid lying to the
compiler about object sizes. Calls into struct proto handlers gain casts
that will be removed in the struct proto conversion patch.

No binary changes expected.

Signed-off-by: Kees Cook 
Link: https://patch.msgid.link/20251104002617.2752303-3-kees@kernel.org
Signed-off-by: Jakub Kicinski

net: Convert proto_ops bind() callbacks to use sockaddr_unsized

2025-11-05T03:10:32+00:00

Update all struct proto_ops bind() callback function prototypes from
"struct sockaddr *" to "struct sockaddr_unsized *" to avoid lying to the
compiler about object sizes. Calls into struct proto handlers gain casts
that will be removed in the struct proto conversion patch.

No binary changes expected.

Signed-off-by: Kees Cook 
Link: https://patch.msgid.link/20251104002617.2752303-2-kees@kernel.org
Signed-off-by: Jakub Kicinski

net: nfc: nci: Add parameter validation for packet data

2025-09-30T08:27:14+00:00

Syzbot reported an uninitialized value bug in nci_init_req, which was
introduced by commit 5aca7966d2a7 ("Merge tag
'perf-tools-fixes-for-v6.17-2025-09-16' of
git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools").

This bug arises due to very limited and poor input validation
that was done at nic_valid_size(). This validation only
validates the skb->len (directly reflects size provided at the
userspace interface) with the length provided in the buffer
itself (interpreted as NCI_HEADER). This leads to the processing
of memory content at the address assuming the correct layout
per what opcode requires there. This leads to the accesses to
buffer of `skb_buff->data` which is not assigned anything yet.

Following the same silent drop of packets of invalid sizes at
`nic_valid_size()`, add validation of the data in the respective
handlers and return error values in case of failure. Release
the skb if error values are returned from handlers in
`nci_nft_packet` and effectively do a silent drop

Possible TODO: because we silently drop the packets, the
call to `nci_request` will be waiting for completion of request
and will face timeouts. These timeouts can get excessively logged
in the dmesg. A proper handling of them may require to export
`nci_request_cancel` (or propagate error handling from the
nft packets handlers).

Reported-by: syzbot+740e04c2a93467a0f8c8@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=740e04c2a93467a0f8c8
Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation")
Tested-by: syzbot+740e04c2a93467a0f8c8@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Deepak Sharma 
Reviewed-by: Vadim Fedorenko 
Link: https://patch.msgid.link/20250925132846.213425-1-deepak.sharma.472935@gmail.com
Signed-off-by: Paolo Abeni

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2025-06-19T20:00:24+00:00

Cross-merge networking fixes after downstream PR (net-6.16-rc3).

No conflicts or adjacent changes.

Signed-off-by: Jakub Kicinski

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

2025-06-19T15:33:54+00:00

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

nfc: Remove checks for nla_data returning NULL

2025-06-18T21:17:32+00:00

The implementation of nla_data is as follows:

static inline void *nla_data(const struct nlattr *nla)
{
	return (char *) nla + NLA_HDRLEN;
}

Excluding the case where nla is exactly -NLA_HDRLEN, it will not return
NULL. And it seems misleading to assume that it can, other than in this
corner case. So drop checks for this condition.

Flagged by Smatch.

Compile tested only.

Signed-off-by: Simon Horman 
Reviewed-by: Krzysztof Kozlowski 
Link: https://patch.msgid.link/20250617-nfc-null-data-v1-1-c7525ead2e95@kernel.org
Signed-off-by: Jakub Kicinski

treewide, timers: Rename from_timer() to timer_container_of()

2025-06-08T07:07:37+00:00

Move this API to the canonical timer_*() namespace.

[ tglx: Redone against pre rc1 ]

Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com