================================ WARNING: inconsistent lock state 5.9.0-rc8-next-20201008-syzkaller #0 Not tainted -------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. syz-executor.2/8511 [HC0[0]:SC0[0]:HE1:SE1] takes: ffff8880161fdc18 (&xa->xa_lock#8){+.?.}-{2:2}, at: spin_lock include/linux/spinlock.h:354 [inline] ffff8880161fdc18 (&xa->xa_lock#8){+.?.}-{2:2}, at: io_uring_add_task_file fs/io_uring.c:8607 [inline] ffff8880161fdc18 (&xa->xa_lock#8){+.?.}-{2:2}, at: io_uring_add_task_file+0x207/0x430 fs/io_uring.c:8590 {IN-SOFTIRQ-W} state was registered at: lock_acquire+0x1f2/0xaa0 kernel/locking/lockdep.c:5419 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x94/0xd0 kernel/locking/spinlock.c:159 xa_destroy+0xaa/0x350 lib/xarray.c:2205 __io_uring_free+0x60/0xc0 fs/io_uring.c:7693 io_uring_free include/linux/io_uring.h:40 [inline] __put_task_struct+0xff/0x3f0 kernel/fork.c:732 put_task_struct include/linux/sched/task.h:111 [inline] delayed_put_task_struct+0x1f6/0x340 kernel/exit.c:172 rcu_do_batch kernel/rcu/tree.c:2484 [inline] rcu_core+0x645/0x1240 kernel/rcu/tree.c:2718 __do_softirq+0x203/0xab6 kernel/softirq.c:298 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0x9b/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:393 [inline] __irq_exit_rcu kernel/softirq.c:423 [inline] irq_exit_rcu+0x235/0x280 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0x51/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631 arch_local_irq_restore arch/x86/include/asm/paravirt.h:653 [inline] lock_acquire+0x27b/0xaa0 kernel/locking/lockdep.c:5422 rcu_lock_acquire include/linux/rcupdate.h:253 [inline] rcu_read_lock include/linux/rcupdate.h:642 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:407 [inline] batadv_nc_worker+0x12d/0xe50 net/batman-adv/network-coding.c:718 process_one_work+0x933/0x15a0 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3af/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 irq event stamp: 225 hardirqs last enabled at (225): [] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] hardirqs last enabled at (225): [] _raw_spin_unlock_irqrestore+0x6f/0x90 kernel/locking/spinlock.c:191 hardirqs last disabled at (224): [] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] hardirqs last disabled at (224): [] _raw_spin_lock_irqsave+0xa9/0xd0 kernel/locking/spinlock.c:159 softirqs last enabled at (206): [] read_pnet include/net/net_namespace.h:327 [inline] softirqs last enabled at (206): [] sock_net include/net/sock.h:2521 [inline] softirqs last enabled at (206): [] unix_create1+0x484/0x570 net/unix/af_unix.c:816 softirqs last disabled at (204): [] unix_sockets_unbound net/unix/af_unix.c:133 [inline] softirqs last disabled at (204): [] unix_create1+0x401/0x570 net/unix/af_unix.c:810 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&xa->xa_lock#8); lock(&xa->xa_lock#8); *** DEADLOCK *** 1 lock held by syz-executor.2/8511: #0: ffffffff8a554da0 (rcu_read_lock){....}-{1:2}, at: io_uring_add_task_file fs/io_uring.c:8600 [inline] #0: ffffffff8a554da0 (rcu_read_lock){....}-{1:2}, at: io_uring_add_task_file+0x138/0x430 fs/io_uring.c:8590 stack backtrace: CPU: 1 PID: 8511 Comm: syz-executor.2 Not tainted 5.9.0-rc8-next-20201008-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x198/0x1fb lib/dump_stack.c:118 print_usage_bug kernel/locking/lockdep.c:3715 [inline] valid_state kernel/locking/lockdep.c:3726 [inline] mark_lock_irq kernel/locking/lockdep.c:3929 [inline] mark_lock.cold+0x32/0x74 kernel/locking/lockdep.c:4396 mark_usage kernel/locking/lockdep.c:4299 [inline] __lock_acquire+0x886/0x56d0 kernel/locking/lockdep.c:4771 lock_acquire+0x1f2/0xaa0 kernel/locking/lockdep.c:5419 __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] io_uring_add_task_file fs/io_uring.c:8607 [inline] io_uring_add_task_file+0x207/0x430 fs/io_uring.c:8590 io_uring_get_fd fs/io_uring.c:9116 [inline] io_uring_create fs/io_uring.c:9280 [inline] io_uring_setup+0x2727/0x3660 fs/io_uring.c:9314 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45de29 Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fc3719c4bf8 EFLAGS: 00000206 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 0000000020000080 RCX: 000000000045de29 RDX: 00000000206d4000 RSI: 0000000020000080 RDI: 0000000000000087 RBP: 000000000118bf78 R08: 0000000020000040 R09: 0000000020000040 R10: 0000000020000000 R11: 0000000000000206 R12: 00000000206d4000 R13: 0000000020ee7000 R14: 0000000020000040 R15: 0000000020000000