program: openat$kvm(0xffffffffffffff9c, &(0x7f00000000c0), 0x4400, 0x0) r0 = socket$inet6_tcp(0xa, 0x1, 0x0) r1 = socket$nl_route(0x10, 0x3, 0x0) r2 = socket$inet6_udp(0xa, 0x2, 0x0) ioctl$sock_SIOCGIFINDEX(r2, 0x8933, &(0x7f0000000c80)={'lo\x00', 0x0}) sendmsg$nl_route_sched(r1, &(0x7f0000001200)={0x0, 0xfffffffffffffe4c, &(0x7f0000000000)={&(0x7f00000002c0)=@newqdisc={0x48, 0x24, 0x4ee4e6a52ff56541, 0x0, 0x0, {0x0, 0x0, 0x0, r3, {}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_fq={{0x7}, {0x1c, 0x2, [@TCA_FQ_FLOW_DEFAULT_RATE={0x18, 0x10, 0x3}, @TCA_FQ_BUCKETS_LOG={0x5a00, 0x8, 0x1c}, @TCA_FQ_FLOW_REFILL_DELAY={0x1027, 0x9, 0x5}]}}]}, 0xa2}}, 0x0) close(r0) ioctl$VT_SETMODE(0xffffffffffffffff, 0x5602, &(0x7f0000000080)={0x7, 0x8f, 0xfe7b, 0x2, 0x2}) socket(0x2b, 0x1, 0x1) bind$inet6(r0, &(0x7f0000000040)={0xa, 0x4e22, 0x0, @empty}, 0x1c) listen(r0, 0xfffffffe) r4 = socket$inet_smc(0x2b, 0x1, 0x0) connect$inet(r4, &(0x7f0000000000)={0x2, 0x4e22, @local}, 0x10) [ 73.852509][ T5301] Bluetooth: hci0: command tx timeout [ 73.946206][ T5321] [ 73.947176][ T5321] ====================================================== [ 73.949884][ T5321] WARNING: possible circular locking dependency detected [ 73.952761][ T5321] syzkaller #0 Not tainted [ 73.954604][ T5321] ------------------------------------------------------ [ 73.957428][ T5321] syz.0.0/5321 is trying to acquire lock: [ 73.959762][ T5321] ffff888012a696d8 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x100/0xc50 [ 73.964676][ T5321] [ 73.964676][ T5321] but task is already holding lock: [ 73.967799][ T5321] ffff888012a68260 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x255/0x560 [ 73.971445][ T5321] [ 73.971445][ T5321] which lock already depends on the new lock. [ 73.971445][ T5321] [ 73.975386][ T5321] [ 73.975386][ T5321] the existing dependency chain (in reverse order) is: [ 73.978776][ T5321] [ 73.978776][ T5321] -> #1 (sk_lock-AF_SMC/1){+.+.}-{0:0}: [ 73.981801][ T5321] lock_sock_nested+0x48/0x100 [ 73.983933][ T5321] smc_listen_out+0x109/0x3e0 [ 73.986187][ T5321] smc_listen_work+0x813/0x13f0 [ 73.988553][ T5321] process_scheduled_works+0xaec/0x17a0 [ 73.991199][ T5321] worker_thread+0xda6/0x1360 [ 73.993498][ T5321] kthread+0x726/0x8b0 [ 73.995529][ T5321] ret_from_fork+0x51b/0xa40 [ 73.997791][ T5321] ret_from_fork_asm+0x1a/0x30 [ 74.000153][ T5321] [ 74.000153][ T5321] -> #0 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}: [ 74.004800][ T5321] __lock_acquire+0x15a5/0x2cf0 [ 74.007173][ T5321] lock_acquire+0x106/0x330 [ 74.009493][ T5321] __flush_work+0x700/0xc50 [ 74.011810][ T5321] __cancel_work_sync+0xbe/0x110 [ 74.014252][ T5321] smc_clcsock_release+0x60/0xf0 [ 74.016698][ T5321] __smc_release+0x66b/0x7e0 [ 74.018874][ T5321] smc_close_non_accepted+0xd5/0x1f0 [ 74.021491][ T5321] smc_close_active+0xb67/0xf10 [ 74.023890][ T5321] __smc_release+0x8d/0x7e0 [ 74.026173][ T5321] smc_release+0x2ce/0x560 [ 74.028426][ T5321] sock_close+0xc3/0x240 [ 74.030690][ T5321] __fput+0x44f/0xa70 [ 74.032829][ T5321] task_work_run+0x1d9/0x270 [ 74.035143][ T5321] exit_to_user_mode_loop+0xed/0x480 [ 74.037660][ T5321] do_syscall_64+0x2b7/0xf80 [ 74.039861][ T5321] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 74.042479][ T5321] [ 74.042479][ T5321] other info that might help us debug this: [ 74.042479][ T5321] [ 74.046548][ T5321] Possible unsafe locking scenario: [ 74.046548][ T5321] [ 74.049534][ T5321] CPU0 CPU1 [ 74.051826][ T5321] ---- ---- [ 74.054236][ T5321] lock(sk_lock-AF_SMC/1); [ 74.056332][ T5321] lock((work_completion)(&new_smc->smc_listen_work)); [ 74.060568][ T5321] lock(sk_lock-AF_SMC/1); [ 74.063636][ T5321] lock((work_completion)(&new_smc->smc_listen_work)); [ 74.066695][ T5321] [ 74.066695][ T5321] *** DEADLOCK *** [ 74.066695][ T5321] [ 74.070312][ T5321] 3 locks held by syz.0.0/5321: [ 74.072483][ T5321] #0: ffff8880125947c8 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x9b/0x240 [ 74.077031][ T5321] #1: ffff888012a68260 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x255/0x560 [ 74.081095][ T5321] #2: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x100/0xc50 [ 74.084814][ T5321] [ 74.084814][ T5321] stack backtrace: [ 74.087249][ T5321] CPU: 0 UID: 0 PID: 5321 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 74.087263][ T5321] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 74.087271][ T5321] Call Trace: [ 74.087278][ T5321] [ 74.087321][ T5321] dump_stack_lvl+0xe8/0x150 [ 74.087355][ T5321] print_circular_bug+0x2e1/0x300 [ 74.087371][ T5321] check_noncircular+0x12e/0x150 [ 74.087385][ T5321] __lock_acquire+0x15a5/0x2cf0 [ 74.087403][ T5321] ? do_raw_spin_lock+0x12b/0x2f0 [ 74.087434][ T5321] ? __flush_work+0x100/0xc50 [ 74.087447][ T5321] lock_acquire+0x106/0x330 [ 74.087462][ T5321] ? __flush_work+0x100/0xc50 [ 74.087477][ T5321] ? __flush_work+0x100/0xc50 [ 74.087489][ T5321] __flush_work+0x700/0xc50 [ 74.087500][ T5321] ? __flush_work+0x100/0xc50 [ 74.087512][ T5321] ? __flush_work+0x100/0xc50 [ 74.087524][ T5321] ? __pfx___flush_work+0x10/0x10 [ 74.087536][ T5321] ? __pfx_wq_barrier_func+0x10/0x10 [ 74.087556][ T5321] ? __cancel_work_sync+0x5c/0x110 [ 74.087569][ T5321] __cancel_work_sync+0xbe/0x110 [ 74.087582][ T5321] smc_clcsock_release+0x60/0xf0 [ 74.087604][ T5321] __smc_release+0x66b/0x7e0 [ 74.087622][ T5321] ? __local_bh_enable_ip+0xd0/0x130 [ 74.087634][ T5321] smc_close_non_accepted+0xd5/0x1f0 [ 74.087645][ T5321] smc_close_active+0xb67/0xf10 [ 74.087658][ T5321] ? __pfx_sock_def_readable+0x10/0x10 [ 74.087676][ T5321] __smc_release+0x8d/0x7e0 [ 74.087692][ T5321] ? __local_bh_enable_ip+0xd0/0x130 [ 74.087704][ T5321] smc_release+0x2ce/0x560 [ 74.087722][ T5321] sock_close+0xc3/0x240 [ 74.087738][ T5321] ? __pfx_sock_close+0x10/0x10 [ 74.087754][ T5321] __fput+0x44f/0xa70 [ 74.087769][ T5321] task_work_run+0x1d9/0x270 [ 74.087784][ T5321] ? __pfx_task_work_run+0x10/0x10 [ 74.087800][ T5321] exit_to_user_mode_loop+0xed/0x480 [ 74.087817][ T5321] ? rcu_is_watching+0x15/0xb0 [ 74.087829][ T5321] do_syscall_64+0x2b7/0xf80 [ 74.087842][ T5321] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 74.087854][ T5321] ? trace_irq_disable+0x37/0x100 [ 74.087866][ T5321] ? clear_bhb_loop+0x60/0xb0 [ 74.087879][ T5321] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 74.087891][ T5321] RIP: 0033:0x7f1b30d9aeb9 [ 74.087904][ T5321] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 [ 74.087914][ T5321] RSP: 002b:00007ffc299df2d8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 [ 74.087928][ T5321] RAX: 0000000000000000 RBX: 00007ffc299df3c0 RCX: 00007f1b30d9aeb9 [ 74.087935][ T5321] RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 [ 74.087942][ T5321] RBP: 0000000000012020 R08: 0000000000000001 R09: 0000000000000000 [ 74.087950][ T5321] R10: 00007f1b30bff02c R11: 0000000000000246 R12: 00007ffc299df400 [ 74.087957][ T5321] R13: 00007f1b31015fac R14: 000000000001205f R15: 00007f1b31015fa0 [ 74.087970][ T5321]