====================================================== WARNING: possible circular locking dependency detected 5.12.0-rc8-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/25614 is trying to acquire lock: ffff888021fff7a0 (slock-AF_INET6){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:354 [inline] ffff888021fff7a0 (slock-AF_INET6){+.-.}-{2:2}, at: sctp_addr_wq_timeout_handler+0x1a1/0x550 net/sctp/protocol.c:666 but task is already holding lock: ffff888013414aa0 (&net->sctp.addr_wq_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:359 [inline] ffff888013414aa0 (&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 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x249/0x250 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 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:324 [inline] rcu_is_watching+0x3d/0xc0 kernel/rcu/tree.c:1169 rcu_read_lock_held_common kernel/rcu/update.c:108 [inline] rcu_read_lock_sched_held+0x1c/0x70 kernel/rcu/update.c:123 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x5e9/0x740 kernel/locking/lockdep.c:5482 rcu_lock_acquire include/linux/rcupdate.h:267 [inline] rcu_read_lock include/linux/rcupdate.h:656 [inline] lock_page_memcg+0x69/0x510 mm/memcontrol.c:2142 page_remove_rmap+0x25/0x1430 mm/rmap.c:1348 zap_pte_range mm/memory.c:1270 [inline] zap_pmd_range mm/memory.c:1374 [inline] zap_pud_range mm/memory.c:1403 [inline] zap_p4d_range mm/memory.c:1424 [inline] unmap_page_range+0xe30/0x2650 mm/memory.c:1445 unmap_single_vma+0x198/0x300 mm/memory.c:1490 unmap_vmas+0x16d/0x2f0 mm/memory.c:1522 exit_mmap+0x2a8/0x590 mm/mmap.c:3218 __mmput+0x122/0x470 kernel/fork.c:1090 mmput+0x58/0x60 kernel/fork.c:1111 exit_mm kernel/exit.c:501 [inline] do_exit+0xb0a/0x2a60 kernel/exit.c:812 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 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 *** 3 locks held by syz-executor.3/25614: #0: ffff888011c04558 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:354 [inline] #0: ffff888011c04558 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: zap_pte_range mm/memory.c:1228 [inline] #0: ffff888011c04558 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: zap_pmd_range mm/memory.c:1374 [inline] #0: ffff888011c04558 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: zap_pud_range mm/memory.c:1403 [inline] #0: ffff888011c04558 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: zap_p4d_range mm/memory.c:1424 [inline] #0: ffff888011c04558 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: unmap_page_range+0x7fe/0x2650 mm/memory.c:1445 #1: ffffc90000007d78 ((&net->sctp.addr_wq_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:35 [inline] #1: ffffc90000007d78 ((&net->sctp.addr_wq_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 kernel/time/timer.c:1421 #2: ffff888013414aa0 (&net->sctp.addr_wq_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:359 [inline] #2: ffff888013414aa0 (&net->sctp.addr_wq_lock){+.-.}-{2:2}, at: sctp_addr_wq_timeout_handler+0x38/0x550 net/sctp/protocol.c:626 stack backtrace: CPU: 0 PID: 25614 Comm: syz-executor.3 Not tainted 5.12.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __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 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:324 [inline] RIP: 0010:rcu_is_watching+0x3d/0xc0 kernel/rcu/tree.c:1169 Code: 03 00 83 f8 07 89 c5 0f 87 81 00 00 00 48 8d 3c ed e0 66 0a 8b 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 <75> 5b 48 03 1c ed e0 66 0a 8b 48 b8 00 00 00 00 00 fc ff df 48 8d RSP: 0018:ffffc900022e75c0 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 0000000000035fc0 RCX: ffffffff8159a8a8 RDX: 1ffffffff1614cdc RSI: 0000000000000003 RDI: ffffffff8b0a66e0 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8dc52b0f R10: fffffbfff1b8a561 R11: 0000000000000000 R12: 0000000000000001 R13: ffffffff8bf74360 R14: 0000000000000000 R15: 0000000000000000 rcu_read_lock_held_common kernel/rcu/update.c:108 [inline] rcu_read_lock_sched_held+0x1c/0x70 kernel/rcu/update.c:123 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x5e9/0x740 kernel/locking/lockdep.c:5482 rcu_lock_acquire include/linux/rcupdate.h:267 [inline] rcu_read_lock include/linux/rcupdate.h:656 [inline] lock_page_memcg+0x69/0x510 mm/memcontrol.c:2142 page_remove_rmap+0x25/0x1430 mm/rmap.c:1348 zap_pte_range mm/memory.c:1270 [inline] zap_pmd_range mm/memory.c:1374 [inline] zap_pud_range mm/memory.c:1403 [inline] zap_p4d_range mm/memory.c:1424 [inline] unmap_page_range+0xe30/0x2650 mm/memory.c:1445 unmap_single_vma+0x198/0x300 mm/memory.c:1490 unmap_vmas+0x16d/0x2f0 mm/memory.c:1522 exit_mmap+0x2a8/0x590 mm/mmap.c:3218 __mmput+0x122/0x470 kernel/fork.c:1090 mmput+0x58/0x60 kernel/fork.c:1111 exit_mm kernel/exit.c:501 [inline] do_exit+0xb0a/0x2a60 kernel/exit.c:812 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 RIP: 0033:0x4665f9 Code: Unable to access opcode bytes at RIP 0x4665cf. RSP: 002b:00007efe5efb0218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000000 RBX: 000000000056bf68 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056bf68 RBP: 000000000056bf60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf6c R13: 0000000000a9fb1f R14: 00007efe5efb0300 R15: 0000000000022000