Re: [syzbot] [wireless?] INFO: task hung in rfkill_unregister (3)

[Johannes Berg]

On Wed, 2023-06-07 at 02:58 -0700, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    eb0f1697d729 Merge branch 'for-next/core', remote-tracking..
> git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
> console output: https://syzkaller.appspot.com/x/log.txt?x=17b656a5280000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=8860074b9a9d6c45
> dashboard link: https://syzkaller.appspot.com/bug?extid=bb540a4bbfb4ae3b425d
> compiler:       Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
> userspace arch: arm64
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=122665a3280000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13dc1c59280000
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/034232da7cff/disk-eb0f1697.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/b11411bec33e/vmlinux-eb0f1697.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/a53c52e170dd/Image-eb0f1697.gz.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+bb540a4bbfb4ae3b425d@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> INFO: task syz-executor410:6034 blocked for more than 143 seconds.
>       Not tainted 6.4.0-rc3-syzkaller-geb0f1697d729 #0
> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> task:syz-executor410 state:D stack:0     pid:6034  ppid:5996   flags:0x0000000c
> Call trace:
>  __switch_to+0x320/0x754 arch/arm64/kernel/process.c:556
>  context_switch kernel/sched/core.c:5343 [inline]
>  __schedule+0x1368/0x23b8 kernel/sched/core.c:6669
>  schedule+0xc4/0x170 kernel/sched/core.c:6745
>  schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6804
>  __mutex_lock_common+0xbd8/0x21a0 kernel/locking/mutex.c:679
>  __mutex_lock kernel/locking/mutex.c:747 [inline]
>  mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:799
>  rfkill_unregister+0xb8/0x210 net/rfkill/core.c:1130
>  nfc_unregister_device+0x98/0x290 net/nfc/core.c:1167
>  nci_unregister_device+0x1dc/0x21c net/nfc/nci/core.c:1303
>  virtual_ncidev_close+0x5c/0xa0 drivers/nfc/virtual_ncidev.c:163

This seems like an issue with the virtual NFC device. I feel we had this
before?

johannes