=============================
WARNING: suspicious RCU usage
5.16.0-rc4-next-20211210-syzkaller #0 Not tainted
-----------------------------
kernel/sched/core.c:9545 Illegal context switch in RCU-bh read-side critical section!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
8 locks held by kworker/1:6/3678:
 #0: ffff888023334938 ((wq_completion)ceph-msgr){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888023334938 ((wq_completion)ceph-msgr){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff888023334938 ((wq_completion)ceph-msgr){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline]
 #0: ffff888023334938 ((wq_completion)ceph-msgr){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:631 [inline]
 #0: ffff888023334938 ((wq_completion)ceph-msgr){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:658 [inline]
 #0: ffff888023334938 ((wq_completion)ceph-msgr){+.+.}-{0:0}, at: process_one_work+0x890/0x1680 kernel/workqueue.c:2278
 #1: ffffc90002bcfdb0 ((work_completion)(&(&con->work)->work)){+.+.}-{0:0}, at: process_one_work+0x8c4/0x1680 kernel/workqueue.c:2282
 #2: ffff88801f7d4568 (&con->mutex){+.+.}-{3:3}, at: ceph_con_workfn+0x44/0x1510 net/ceph/messenger.c:1500
 #3: ffff888019fa3330 (&socket_class){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1675 [inline]
 #3: ffff888019fa3330 (&socket_class){+.+.}-{0:0}, at: inet_stream_connect+0x3f/0xa0 net/ipv4/af_inet.c:721
 #4: ffffffff8bb818a0 (rcu_read_lock){....}-{1:2}, at: ip6_route_output_flags+0x0/0x320 net/ipv6/route.c:778
 #5: ffffffff8bb818a0 (rcu_read_lock){....}-{1:2}, at: fib_rules_lookup+0x0/0xc20 include/linux/list.h:292
 #6: ffffffff8bb818a0 (rcu_read_lock){....}-{1:2}, at: ip6_pol_route+0x156/0x11e0 net/ipv6/route.c:2217
 #7: ffffffff8bb81840 (rcu_read_lock_bh){....}-{1:2}, at: rt6_probe net/ipv6/route.c:632 [inline]
 #7: ffffffff8bb81840 (rcu_read_lock_bh){....}-{1:2}, at: find_match.part.0+0x35a/0xd00 net/ipv6/route.c:752

stack backtrace:
CPU: 1 PID: 3678 Comm: kworker/1:6 Not tainted 5.16.0-rc4-next-20211210-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: ceph-msgr ceph_con_workfn
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 __might_resched+0x235/0x2c0 kernel/sched/core.c:9545
 might_alloc include/linux/sched/mm.h:256 [inline]
 slab_pre_alloc_hook mm/slab.h:739 [inline]
 slab_alloc_node mm/slub.c:3145 [inline]
 slab_alloc mm/slub.c:3239 [inline]
 kmem_cache_alloc_trace+0x25d/0x2c0 mm/slub.c:3256
 kmalloc include/linux/slab.h:581 [inline]
 kzalloc include/linux/slab.h:715 [inline]
 ref_tracker_alloc+0xe1/0x430 lib/ref_tracker.c:74
 netdev_tracker_alloc include/linux/netdevice.h:3860 [inline]
 dev_hold_track include/linux/netdevice.h:3877 [inline]
 rt6_probe net/ipv6/route.c:661 [inline]
 find_match.part.0+0xac9/0xd00 net/ipv6/route.c:752
 find_match net/ipv6/route.c:825 [inline]
 __find_rr_leaf+0x17f/0xd20 net/ipv6/route.c:826
 find_rr_leaf net/ipv6/route.c:847 [inline]
 rt6_select net/ipv6/route.c:891 [inline]
 fib6_table_lookup+0x649/0xa20 net/ipv6/route.c:2185
 ip6_pol_route+0x1c5/0x11e0 net/ipv6/route.c:2221
 pol_lookup_func include/net/ip6_fib.h:580 [inline]
 __fib6_rule_action net/ipv6/fib6_rules.c:232 [inline]
 fib6_rule_action+0x269/0x9f0 net/ipv6/fib6_rules.c:266
 fib_rules_lookup+0x354/0xc20 net/core/fib_rules.c:318
 fib6_rule_lookup+0x4ba/0x6f0 net/ipv6/fib6_rules.c:107
 ip6_route_output_flags_noref+0x2e2/0x380 net/ipv6/route.c:2629
 ip6_route_output_flags+0x72/0x320 net/ipv6/route.c:2642
 ip6_route_output include/net/ip6_route.h:98 [inline]
 ip6_dst_lookup_tail+0x5ab/0x1620 net/ipv6/ip6_output.c:1070
 ip6_dst_lookup_flow+0x8c/0x1d0 net/ipv6/ip6_output.c:1200
 tcp_v6_connect+0xda3/0x1e00 net/ipv6/tcp_ipv6.c:283
 __inet_stream_connect+0x8cf/0xed0 net/ipv4/af_inet.c:658
 inet_stream_connect+0x53/0xa0 net/ipv4/af_inet.c:722
 ceph_tcp_connect+0x5fd/0x960 net/ceph/messenger.c:457
 ceph_con_v1_try_write+0xb64/0x2980 net/ceph/messenger_v1.c:1379
 ceph_con_workfn+0x39b/0x1510 net/ceph/messenger.c:1542
 process_one_work+0x9ac/0x1680 kernel/workqueue.c:2307
 worker_thread+0x652/0x11c0 kernel/workqueue.c:2454
 kthread+0x405/0x4f0 kernel/kthread.c:345
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
BUG: sleeping function called from invalid context at include/linux/sched/mm.h:256
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 3678, name: kworker/1:6
preempt_count: 200, expected: 0
RCU nest depth: 3, expected: 0
8 locks held by kworker/1:6/3678:
 #0: ffff888023334938 ((wq_completion)ceph-msgr){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888023334938 ((wq_completion)ceph-msgr){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff888023334938 ((wq_completion)ceph-msgr){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline]
 #0: ffff888023334938 ((wq_completion)ceph-msgr){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:631 [inline]
 #0: ffff888023334938 ((wq_completion)ceph-msgr){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:658 [inline]
 #0: ffff888023334938 ((wq_completion)ceph-msgr){+.+.}-{0:0}, at: process_one_work+0x890/0x1680 kernel/workqueue.c:2278
 #1: ffffc90002bcfdb0 ((work_completion)(&(&con->work)->work)){+.+.}-{0:0}, at: process_one_work+0x8c4/0x1680 kernel/workqueue.c:2282
 #2: ffff88801f7d4568 (&con->mutex){+.+.}-{3:3}, at: ceph_con_workfn+0x44/0x1510 net/ceph/messenger.c:1500
 #3: ffff888019fa3330 (&socket_class){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1675 [inline]
 #3: ffff888019fa3330 (&socket_class){+.+.}-{0:0}, at: inet_stream_connect+0x3f/0xa0 net/ipv4/af_inet.c:721
 #4: ffffffff8bb818a0 (rcu_read_lock){....}-{1:2}, at: ip6_route_output_flags+0x0/0x320 net/ipv6/route.c:778
 #5: ffffffff8bb818a0 (rcu_read_lock){....}-{1:2}, at: fib_rules_lookup+0x0/0xc20 include/linux/list.h:292
 #6: ffffffff8bb818a0 (rcu_read_lock){....}-{1:2}, at: ip6_pol_route+0x156/0x11e0 net/ipv6/route.c:2217
 #7: ffffffff8bb81840 (rcu_read_lock_bh){....}-{1:2}, at: rt6_probe net/ipv6/route.c:632 [inline]
 #7: ffffffff8bb81840 (rcu_read_lock_bh){....}-{1:2}, at: find_match.part.0+0x35a/0xd00 net/ipv6/route.c:752
Preemption disabled at:
[<ffffffff87f62c37>] local_bh_disable include/linux/bottom_half.h:20 [inline]
[<ffffffff87f62c37>] rcu_read_lock_bh include/linux/rcupdate.h:746 [inline]
[<ffffffff87f62c37>] rt6_probe net/ipv6/route.c:633 [inline]
[<ffffffff87f62c37>] find_match.part.0+0x377/0xd00 net/ipv6/route.c:752
CPU: 1 PID: 3678 Comm: kworker/1:6 Not tainted 5.16.0-rc4-next-20211210-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: ceph-msgr ceph_con_workfn
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 __might_resched.cold+0x222/0x26b kernel/sched/core.c:9583
 might_alloc include/linux/sched/mm.h:256 [inline]
 slab_pre_alloc_hook mm/slab.h:739 [inline]
 slab_alloc_node mm/slub.c:3145 [inline]
 slab_alloc mm/slub.c:3239 [inline]
 kmem_cache_alloc_trace+0x25d/0x2c0 mm/slub.c:3256
 kmalloc include/linux/slab.h:581 [inline]
 kzalloc include/linux/slab.h:715 [inline]
 ref_tracker_alloc+0xe1/0x430 lib/ref_tracker.c:74
 netdev_tracker_alloc include/linux/netdevice.h:3860 [inline]
 dev_hold_track include/linux/netdevice.h:3877 [inline]
 rt6_probe net/ipv6/route.c:661 [inline]
 find_match.part.0+0xac9/0xd00 net/ipv6/route.c:752
 find_match net/ipv6/route.c:825 [inline]
 __find_rr_leaf+0x17f/0xd20 net/ipv6/route.c:826
 find_rr_leaf net/ipv6/route.c:847 [inline]
 rt6_select net/ipv6/route.c:891 [inline]
 fib6_table_lookup+0x649/0xa20 net/ipv6/route.c:2185
 ip6_pol_route+0x1c5/0x11e0 net/ipv6/route.c:2221
 pol_lookup_func include/net/ip6_fib.h:580 [inline]
 __fib6_rule_action net/ipv6/fib6_rules.c:232 [inline]
 fib6_rule_action+0x269/0x9f0 net/ipv6/fib6_rules.c:266
 fib_rules_lookup+0x354/0xc20 net/core/fib_rules.c:318
 fib6_rule_lookup+0x4ba/0x6f0 net/ipv6/fib6_rules.c:107
 ip6_route_output_flags_noref+0x2e2/0x380 net/ipv6/route.c:2629
 ip6_route_output_flags+0x72/0x320 net/ipv6/route.c:2642
 ip6_route_output include/net/ip6_route.h:98 [inline]
 ip6_dst_lookup_tail+0x5ab/0x1620 net/ipv6/ip6_output.c:1070
 ip6_dst_lookup_flow+0x8c/0x1d0 net/ipv6/ip6_output.c:1200
 tcp_v6_connect+0xda3/0x1e00 net/ipv6/tcp_ipv6.c:283
 __inet_stream_connect+0x8cf/0xed0 net/ipv4/af_inet.c:658
 inet_stream_connect+0x53/0xa0 net/ipv4/af_inet.c:722
 ceph_tcp_connect+0x5fd/0x960 net/ceph/messenger.c:457
 ceph_con_v1_try_write+0xb64/0x2980 net/ceph/messenger_v1.c:1379
 ceph_con_workfn+0x39b/0x1510 net/ceph/messenger.c:1542
 process_one_work+0x9ac/0x1680 kernel/workqueue.c:2307
 worker_thread+0x652/0x11c0 kernel/workqueue.c:2454
 kthread+0x405/0x4f0 kernel/kthread.c:345
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
usb 6-1: USB disconnect, device number 17
Unregistered device Elgato EyeTV DTT Deluxe
as10x_usb: device has been disconnected