Re: INFO: trying to register non-static key in pfifo_fast_reset

[Eric Biggers]

On Sun, Dec 17, 2017 at 01:56:01AM -0800, syzbot wrote:
> Hello,
> 
> syzkaller hit the following crash on
> 41d8c16909ebda40f7b4982a7f5e2ad102705ade
> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master
> compiler: gcc (GCC) 7.1.1 20170620
> .config is attached
> Raw console output is attached.
> C reproducer is attached
> syzkaller reproducer is attached. See https://goo.gl/kgGztJ
> for information about syzkaller reproducers
> 
> 
> RBP: 0000000000000008 R08: 0000000000000001 R09: 0000000000000034
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000030657267
> R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000
> INFO: trying to register non-static key.
> the code is fine but needs lockdep annotation.
> turning off the locking correctness validator.
> CPU: 1 PID: 3119 Comm: syzkaller228956 Not tainted 4.15.0-rc3-next-20171213+
> #66
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> Call Trace:
>  __dump_stack lib/dump_stack.c:17 [inline]
>  dump_stack+0xe9/0x14b lib/dump_stack.c:53
>  register_lock_class+0x164/0x5d0 kernel/locking/lockdep.c:752
>  __lock_acquire+0xb4/0x1430 kernel/locking/lockdep.c:3314
>  lock_acquire+0xbf/0x220 kernel/locking/lockdep.c:3914
>  __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
>  _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168
>  spin_lock_bh include/linux/spinlock.h:315 [inline]
>  ptr_ring_consume_bh include/linux/ptr_ring.h:349 [inline]
>  skb_array_consume_bh include/linux/skb_array.h:136 [inline]
>  pfifo_fast_reset+0x9a/0x1b0 net/sched/sch_generic.c:662
>  qdisc_destroy+0x94/0x210 net/sched/sch_generic.c:896
>  qdisc_create_dflt+0xa6/0xb0 net/sched/sch_generic.c:840
>  mq_init+0x105/0x150 net/sched/sch_mq.c:61
>  qdisc_create_dflt+0x60/0xb0 net/sched/sch_generic.c:837
>  attach_default_qdiscs net/sched/sch_generic.c:972 [inline]
>  dev_activate+0x363/0x3b0 net/sched/sch_generic.c:1011
>  __dev_open+0x119/0x180 net/core/dev.c:1389
>  __dev_change_flags+0x218/0x270 net/core/dev.c:6836
>  dev_change_flags+0x30/0x70 net/core/dev.c:6905
>  dev_ifsioc+0x3c2/0x520 net/core/dev_ioctl.c:257
>  dev_ioctl+0x15d/0x7a0 net/core/dev_ioctl.c:566
>  sock_do_ioctl+0x59/0x60 net/socket.c:971
>  sock_ioctl+0x211/0x320 net/socket.c:1061
>  vfs_ioctl fs/ioctl.c:46 [inline]
>  do_vfs_ioctl+0xaf/0x840 fs/ioctl.c:686
>  SYSC_ioctl fs/ioctl.c:701 [inline]
>  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
>  entry_SYSCALL_64_fastpath+0x1f/0x96
> RIP: 0033:0x4444b9
> RSP: 002b:00007ffcad5a5418
> 
> 
> ---
> This bug is generated by a dumb bot. It may contain errors.
> See https://goo.gl/tpsmEJ for details.
> Direct all questions to syzkaller@xxxxxxxxxxxxxxxxx
> Please credit me with: Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
> 
> syzbot will keep track of this bug report.
> Once a fix for this bug is merged into any tree, reply to this email with:
> #syz fix: exact-commit-title

No longer occurring, seems to have been fixed by commit 1df94c3c5dadb:

#syz fix: net_sched: properly check for empty skb array on error path

- Eric