======================================================
WARNING: possible circular locking dependency detected
5.12.0-rc7-syzkaller #0 Not tainted
------------------------------------------------------
kworker/u4:9/18161 is trying to acquire lock:
ffff888027ea1a20 (slock-AF_INET6){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:354 [inline]
ffff888027ea1a20 (slock-AF_INET6){+.-.}-{2:2}, at: sctp_addr_wq_timeout_handler+0x1a1/0x550 net/sctp/protocol.c:666
but task is already holding lock:
ffff88802d9fa7e0 (&net->sctp.addr_wq_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:359 [inline]
ffff88802d9fa7e0 (&net->sctp.addr_wq_lock){+.-.}-{2:2}, at: sctp_addr_wq_timeout_handler+0x38/0x550 net/sctp/protocol.c:626
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&net->sctp.addr_wq_lock){+.-.}-{2:2}:
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175
spin_lock_bh include/linux/spinlock.h:359 [inline]
sctp_destroy_sock+0x204/0x440 net/sctp/socket.c:5028
sctp_v6_destroy_sock+0x11/0x20 net/sctp/socket.c:9528
sk_common_release+0x64/0x390 net/core/sock.c:3264
sctp_close+0x4da/0x940 net/sctp/socket.c:1531
inet_release+0x12e/0x280 net/ipv4/af_inet.c:431
inet6_release+0x4c/0x70 net/ipv6/af_inet6.c:478
__sock_release+0xcd/0x280 net/socket.c:599
sock_close+0x18/0x20 net/socket.c:1258
__fput+0x288/0x920 fs/file_table.c:280
task_work_run+0xdd/0x1a0 kernel/task_work.c:140
exit_task_work include/linux/task_work.h:30 [inline]
do_exit+0xbfc/0x2a60 kernel/exit.c:825
do_group_exit+0x125/0x310 kernel/exit.c:922
get_signal+0x47f/0x2150 kernel/signal.c:2781
arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:789
handle_signal_work kernel/entry/common.c:147 [inline]
exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:208
__syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #0 (slock-AF_INET6){+.-.}-{2:2}:
check_prev_add kernel/locking/lockdep.c:2937 [inline]
check_prevs_add kernel/locking/lockdep.c:3060 [inline]
validate_chain kernel/locking/lockdep.c:3675 [inline]
__lock_acquire+0x2b14/0x54c0 kernel/locking/lockdep.c:4901
lock_acquire kernel/locking/lockdep.c:5511 [inline]
lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5476
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:354 [inline]
sctp_addr_wq_timeout_handler+0x1a1/0x550 net/sctp/protocol.c:666
call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1431
expire_timers kernel/time/timer.c:1476 [inline]
__run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1745
__run_timers kernel/time/timer.c:1726 [inline]
run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1758
__do_softirq+0x29b/0x9f6 kernel/softirq.c:345
invoke_softirq kernel/softirq.c:221 [inline]
__irq_exit_rcu kernel/softirq.c:422 [inline]
irq_exit_rcu+0x134/0x200 kernel/softirq.c:434
sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100
asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
lock_release+0x3f1/0x720 kernel/locking/lockdep.c:5519
rcu_lock_release include/linux/rcupdate.h:272 [inline]
rcu_read_unlock include/linux/rcupdate.h:710 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
batadv_nc_worker+0x7a3/0xe50 net/batman-adv/network-coding.c:715
process_one_work+0x98d/0x1600 kernel/workqueue.c:2275
worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
kthread+0x3b1/0x4a0 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&net->sctp.addr_wq_lock);
lock(slock-AF_INET6);
lock(&net->sctp.addr_wq_lock);
lock(slock-AF_INET6);
*** DEADLOCK ***
4 locks held by kworker/u4:9/18161:
#0: ffff888147bcf938 ((wq_completion)bat_events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888147bcf938 ((wq_completion)bat_events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
#0: ffff888147bcf938 ((wq_completion)bat_events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
#0: ffff888147bcf938 ((wq_completion)bat_events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
#0: ffff888147bcf938 ((wq_completion)bat_events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
#0: ffff888147bcf938 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2246
#1: ffffc90009487da8 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2250
#2: ffffc90000dc0d78 ((&net->sctp.addr_wq_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:35 [inline]
#2: ffffc90000dc0d78 ((&net->sctp.addr_wq_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 kernel/time/timer.c:1421
#3: ffff88802d9fa7e0 (&net->sctp.addr_wq_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:359 [inline]
#3: ffff88802d9fa7e0 (&net->sctp.addr_wq_lock){+.-.}-{2:2}, at: sctp_addr_wq_timeout_handler+0x38/0x550 net/sctp/protocol.c:626
stack backtrace:
CPU: 1 PID: 18161 Comm: kworker/u4:9 Not tainted 5.12.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x141/0x1d7 lib/dump_stack.c:120
check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2128
check_prev_add kernel/locking/lockdep.c:2937 [inline]
check_prevs_add kernel/locking/lockdep.c:3060 [inline]
validate_chain kernel/locking/lockdep.c:3675 [inline]
__lock_acquire+0x2b14/0x54c0 kernel/locking/lockdep.c:4901
lock_acquire kernel/locking/lockdep.c:5511 [inline]
lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5476
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:354 [inline]
sctp_addr_wq_timeout_handler+0x1a1/0x550 net/sctp/protocol.c:666
call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1431
expire_timers kernel/time/timer.c:1476 [inline]
__run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1745
__run_timers kernel/time/timer.c:1726 [inline]
run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1758
__do_softirq+0x29b/0x9f6 kernel/softirq.c:345
invoke_softirq kernel/softirq.c:221 [inline]
__irq_exit_rcu kernel/softirq.c:422 [inline]
irq_exit_rcu+0x134/0x200 kernel/softirq.c:434
sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100
</IRQ>
asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:lock_release+0x3f1/0x720 kernel/locking/lockdep.c:5519
Code: 7e 83 f8 01 0f 85 83 01 00 00 9c 58 f6 c4 02 0f 85 6e 01 00 00 48 f7 04 24 00 02 00 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c5 48 c7 45 00 00 00 00 00 c7 45 08 00 00 00 00 48 8b 84 24
RSP: 0018:ffffc90009487bc8 EFLAGS: 00000206
RAX: dffffc0000000000 RBX: 5a3d9261ebe5ea87 RCX: ffffc90009487c18
RDX: 1ffff1100e48abd4 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 1ffff92001290f7b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000003 R14: ffff888072455ea8 R15: ffff8880724554c0
rcu_lock_release include/linux/rcupdate.h:272 [inline]
rcu_read_unlock include/linux/rcupdate.h:710 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
batadv_nc_worker+0x7a3/0xe50 net/batman-adv/network-coding.c:715
process_one_work+0x98d/0x1600 kernel/workqueue.c:2275
worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
kthread+0x3b1/0x4a0 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294