================================ WARNING: inconsistent lock state 6.0.0-rc6-syzkaller-00309-g1a61b828566f #0 Not tainted -------------------------------- inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. kworker/u16:4/3761 [HC1[1]:SC0[0]:HE0:SE1] takes: ffff8880430c1018 (&clnt->lock){?.+.}-{2:2}, at: p9_tag_remove net/9p/client.c:367 [inline] ffff8880430c1018 (&clnt->lock){?.+.}-{2:2}, at: p9_req_put net/9p/client.c:375 [inline] ffff8880430c1018 (&clnt->lock){?.+.}-{2:2}, at: p9_req_put+0xc6/0x250 net/9p/client.c:372 {HARDIRQ-ON-W} state was registered at: lock_acquire kernel/locking/lockdep.c:5666 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:349 [inline] p9_fd_request+0x85/0x330 net/9p/trans_fd.c:672 p9_client_rpc+0x2f0/0xce0 net/9p/client.c:660 p9_client_version net/9p/client.c:880 [inline] p9_client_create+0xaec/0x1070 net/9p/client.c:985 v9fs_session_init+0x1e2/0x1810 fs/9p/v9fs.c:408 v9fs_mount+0xba/0xc90 fs/9p/vfs_super.c:126 legacy_get_tree+0x105/0x220 fs/fs_context.c:610 vfs_get_tree+0x89/0x2f0 fs/super.c:1530 do_new_mount fs/namespace.c:3040 [inline] path_mount+0x1326/0x1e20 fs/namespace.c:3370 do_mount fs/namespace.c:3383 [inline] __do_sys_mount fs/namespace.c:3591 [inline] __se_sys_mount fs/namespace.c:3568 [inline] __ia32_sys_mount+0x27e/0x300 fs/namespace.c:3568 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 irq event stamp: 35178190 hardirqs last enabled at (35178189): [] asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 hardirqs last disabled at (35178190): [] common_interrupt+0x11/0xc0 arch/x86/kernel/irq.c:240 softirqs last enabled at (35178186): [] invoke_softirq kernel/softirq.c:445 [inline] softirqs last enabled at (35178186): [] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 softirqs last disabled at (35178173): [] invoke_softirq kernel/softirq.c:445 [inline] softirqs last disabled at (35178173): [] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&clnt->lock); lock(&clnt->lock); *** DEADLOCK *** 4 locks held by kworker/u16:4/3761: #0: ffff8880119c6938 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline] ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline] ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260 #1: ffffc90003e8fda8 (net_cleanup_work ){+.+.}-{0:0} , at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264 #2: ffffffff8d79d950 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb00 net/core/net_namespace.c:557 #3: ffff88804528c020 (&chan->lock#2){-...}-{2:2}, at: req_done+0xcf/0x2e0 net/9p/trans_virtio.c:139 stack backtrace: CPU: 1 PID: 3761 Comm: kworker/u16:4 Not tainted 6.0.0-rc6-syzkaller-00309-g1a61b828566f #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_usage_bug kernel/locking/lockdep.c:3961 [inline] valid_state kernel/locking/lockdep.c:3973 [inline] mark_lock_irq kernel/locking/lockdep.c:4176 [inline] mark_lock.part.0.cold+0x18/0xd8 kernel/locking/lockdep.c:4632 mark_lock kernel/locking/lockdep.c:4596 [inline] mark_usage kernel/locking/lockdep.c:4524 [inline] __lock_acquire+0x14a2/0x56d0 kernel/locking/lockdep.c:5007 lock_acquire kernel/locking/lockdep.c:5666 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 p9_tag_remove net/9p/client.c:367 [inline] p9_req_put net/9p/client.c:375 [inline] p9_req_put+0xc6/0x250 net/9p/client.c:372 req_done+0x1de/0x2e0 net/9p/trans_virtio.c:148 vring_interrupt drivers/virtio/virtio_ring.c:2462 [inline] vring_interrupt+0x29d/0x3d0 drivers/virtio/virtio_ring.c:2437 __handle_irq_event_percpu+0x227/0x870 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0xa7/0x1e0 kernel/irq/handle.c:210 handle_edge_irq+0x25f/0xd00 kernel/irq/chip.c:819 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline] handle_irq arch/x86/kernel/irq.c:231 [inline] __common_interrupt+0x9d/0x210 arch/x86/kernel/irq.c:250 common_interrupt+0xa4/0xc0 arch/x86/kernel/irq.c:240 asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:640 RIP: 0010:lock_release+0x3f1/0x780 kernel/locking/lockdep.c:5674 Code: 7e 83 f8 01 0f 85 cb 01 00 00 9c 58 f6 c4 02 0f 85 b6 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:ffffc90003e8fa78 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 3b6b307dda3b8609 RCX: ffffc90003e8fac8 RDX: 1ffff11002da2c5d RSI: 0000000000000000 RDI: 0000000000000000 RBP: 1ffff920007d1f51 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 1ffffffff17f2741 R12: 0000000000000003 R13: 0000000000000004 R14: ffff888016d162f0 R15: ffff888016d15880 rcu_lock_release include/linux/rcupdate.h:285 [inline] rcu_read_unlock include/linux/rcupdate.h:739 [inline] inet_twsk_purge+0x55b/0x850 net/ipv4/inet_timewait_sock.c:301 ops_exit_list+0x125/0x170 net/core/net_namespace.c:168 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:595 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 ---------------- Code disassembly (best guess): 0: 7e 83 jle 0xffffff85 2: f8 clc 3: 01 0f add %ecx,(%rdi) 5: 85 cb test %ecx,%ebx 7: 01 00 add %eax,(%rax) 9: 00 9c 58 f6 c4 02 0f add %bl,0xf02c4f6(%rax,%rbx,2) 10: 85 b6 01 00 00 48 test %esi,0x48000001(%rsi) 16: f7 04 24 00 02 00 00 testl $0x200,(%rsp) 1d: 74 01 je 0x20 1f: fb sti 20: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 27: fc ff df * 2a: 48 01 c5 add %rax,%rbp <-- trapping instruction 2d: 48 c7 45 00 00 00 00 movq $0x0,0x0(%rbp) 34: 00 35: c7 45 08 00 00 00 00 movl $0x0,0x8(%rbp) 3c: 48 rex.W 3d: 8b .byte 0x8b 3e: 84 .byte 0x84 3f: 24 .byte 0x24