program: socket$packet(0x11, 0x2, 0x300) r0 = socket$kcm(0x2, 0x3, 0x106) sendmsg$inet(r0, &(0x7f0000000340)={&(0x7f0000000380)={0x2, 0x0, @remote}, 0x10, &(0x7f0000000300)=[{&(0x7f0000000080)="b5fa4fc5060000ffffff970386780df56e5be7070101080a4e7719b506a0977b", 0xffbf}], 0x1}, 0x0) r1 = socket$inet6_tcp(0xa, 0x1, 0x0) close(r1) socket(0x2b, 0x1, 0x1) bind$inet6(r1, &(0x7f0000000040)={0xa, 0x4e22, 0x0, @empty}, 0x1c) r2 = socket$inet6_tcp(0xa, 0x1, 0x0) getsockopt$inet6_tcp_int(r2, 0x6, 0x5, 0x0, &(0x7f0000000000)) listen(r1, 0x0) r3 = socket$inet_smc(0x2b, 0x1, 0x0) connect$inet(r3, &(0x7f0000000000)={0x2, 0x4e22, @local}, 0x10) [ 85.213570][ T5336] [ 85.214665][ T5336] ====================================================== [ 85.217651][ T5336] WARNING: possible circular locking dependency detected [ 85.220622][ T5336] syzkaller #0 Not tainted [ 85.222577][ T5336] ------------------------------------------------------ [ 85.225538][ T5336] syz.0.0/5336 is trying to acquire lock: [ 85.227922][ T5336] ffff888041d58a68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x100/0xc50 [ 85.232671][ T5336] [ 85.232671][ T5336] but task is already holding lock: [ 85.235776][ T5336] ffff888041d58ee0 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x255/0x560 [ 85.239562][ T5336] [ 85.239562][ T5336] which lock already depends on the new lock. [ 85.239562][ T5336] [ 85.243800][ T5336] [ 85.243800][ T5336] the existing dependency chain (in reverse order) is: [ 85.247614][ T5336] [ 85.247614][ T5336] -> #1 (sk_lock-AF_SMC/1){+.+.}-{0:0}: [ 85.250795][ T5336] lock_sock_nested+0x41/0x100 [ 85.253015][ T5336] smc_listen_out+0x109/0x3e0 [ 85.255202][ T5336] smc_listen_work+0x813/0x13f0 [ 85.257439][ T5336] process_scheduled_works+0xb5d/0x1860 [ 85.259930][ T5336] worker_thread+0xa53/0xfc0 [ 85.262029][ T5336] kthread+0x389/0x470 [ 85.263955][ T5336] ret_from_fork+0x514/0xb70 [ 85.266165][ T5336] ret_from_fork_asm+0x1a/0x30 [ 85.268433][ T5336] [ 85.268433][ T5336] -> #0 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}: [ 85.272646][ T5336] __lock_acquire+0x15a5/0x2cf0 [ 85.274974][ T5336] lock_acquire+0x106/0x350 [ 85.277050][ T5336] __flush_work+0x700/0xc50 [ 85.279156][ T5336] __cancel_work_sync+0xbe/0x110 [ 85.281470][ T5336] smc_clcsock_release+0x60/0xf0 [ 85.283758][ T5336] __smc_release+0x66b/0x7e0 [ 85.286039][ T5336] smc_close_non_accepted+0xd5/0x1f0 [ 85.288399][ T5336] smc_close_active+0xb67/0xf10 [ 85.290673][ T5336] __smc_release+0x8d/0x7e0 [ 85.292751][ T5336] smc_release+0x2ce/0x560 [ 85.294878][ T5336] sock_close+0xc3/0x240 [ 85.296864][ T5336] __fput+0x44f/0xa60 [ 85.298782][ T5336] task_work_run+0x1d9/0x270 [ 85.300905][ T5336] exit_to_user_mode_loop+0x193/0x680 [ 85.303378][ T5336] do_syscall_64+0x353/0x580 [ 85.305576][ T5336] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 85.308266][ T5336] [ 85.308266][ T5336] other info that might help us debug this: [ 85.308266][ T5336] [ 85.312381][ T5336] Possible unsafe locking scenario: [ 85.312381][ T5336] [ 85.315455][ T5336] CPU0 CPU1 [ 85.317664][ T5336] ---- ---- [ 85.319916][ T5336] lock(sk_lock-AF_SMC/1); [ 85.321841][ T5336] lock((work_completion)(&new_smc->smc_listen_work)); [ 85.325798][ T5336] lock(sk_lock-AF_SMC/1); [ 85.328663][ T5336] lock((work_completion)(&new_smc->smc_listen_work)); [ 85.331617][ T5336] [ 85.331617][ T5336] *** DEADLOCK *** [ 85.331617][ T5336] [ 85.334935][ T5336] 3 locks held by syz.0.0/5336: [ 85.336976][ T5336] #0: ffff888047283040 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x9b/0x240 [ 85.341244][ T5336] #1: ffff888041d58ee0 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x255/0x560 [ 85.345198][ T5336] #2: ffffffff8e95cc20 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x100/0xc50 [ 85.349073][ T5336] [ 85.349073][ T5336] stack backtrace: [ 85.351575][ T5336] CPU: 0 UID: 0 PID: 5336 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 85.351588][ T5336] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 85.351594][ T5336] Call Trace: [ 85.351602][ T5336] [ 85.351607][ T5336] dump_stack_lvl+0xe8/0x150 [ 85.351623][ T5336] print_circular_bug+0x2e1/0x300 [ 85.351637][ T5336] check_noncircular+0x12e/0x150 [ 85.351650][ T5336] __lock_acquire+0x15a5/0x2cf0 [ 85.351663][ T5336] ? __pfx___schedule+0x10/0x10 [ 85.351679][ T5336] ? irqentry_exit+0x218/0x8b0 [ 85.351688][ T5336] ? irqentry_exit+0x218/0x8b0 [ 85.351697][ T5336] ? trace_irq_disable+0x3b/0x140 [ 85.351714][ T5336] ? __flush_work+0x100/0xc50 [ 85.351725][ T5336] lock_acquire+0x106/0x350 [ 85.351735][ T5336] ? __flush_work+0x100/0xc50 [ 85.351748][ T5336] ? preempt_schedule_thunk+0x16/0x30 [ 85.351763][ T5336] ? __flush_work+0x100/0xc50 [ 85.351775][ T5336] __flush_work+0x700/0xc50 [ 85.351785][ T5336] ? __flush_work+0x100/0xc50 [ 85.351797][ T5336] ? __flush_work+0x100/0xc50 [ 85.351807][ T5336] ? __pfx___flush_work+0x10/0x10 [ 85.351818][ T5336] ? __pfx_wq_barrier_func+0x10/0x10 [ 85.351831][ T5336] ? __cancel_work_sync+0x5c/0x110 [ 85.351842][ T5336] __cancel_work_sync+0xbe/0x110 [ 85.351855][ T5336] smc_clcsock_release+0x60/0xf0 [ 85.351867][ T5336] __smc_release+0x66b/0x7e0 [ 85.351882][ T5336] ? __local_bh_enable_ip+0xd0/0x130 [ 85.351893][ T5336] smc_close_non_accepted+0xd5/0x1f0 [ 85.351909][ T5336] smc_close_active+0xb67/0xf10 [ 85.351922][ T5336] ? __pfx_sock_def_readable+0x10/0x10 [ 85.351935][ T5336] __smc_release+0x8d/0x7e0 [ 85.351948][ T5336] ? __local_bh_enable_ip+0xd0/0x130 [ 85.351959][ T5336] smc_release+0x2ce/0x560 [ 85.351973][ T5336] sock_close+0xc3/0x240 [ 85.351984][ T5336] ? __pfx_sock_close+0x10/0x10 [ 85.351994][ T5336] __fput+0x44f/0xa60 [ 85.352007][ T5336] task_work_run+0x1d9/0x270 [ 85.352023][ T5336] ? __pfx_task_work_run+0x10/0x10 [ 85.352055][ T5336] exit_to_user_mode_loop+0x193/0x680 [ 85.352067][ T5336] ? rcu_is_watching+0x15/0xb0 [ 85.352078][ T5336] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 85.352090][ T5336] do_syscall_64+0x353/0x580 [ 85.352101][ T5336] ? clear_bhb_loop+0x40/0x90 [ 85.352112][ T5336] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 85.352123][ T5336] RIP: 0033:0x7f499779ce59 [ 85.352135][ T5336] 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 [ 85.352143][ T5336] RSP: 002b:00007ffddf23d718 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 [ 85.352155][ T5336] RAX: 0000000000000000 RBX: 00007f4997a17da0 RCX: 00007f499779ce59 [ 85.352162][ T5336] RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 [ 85.352168][ T5336] RBP: 00007f4997a17da0 R08: 00007f4997a16038 R09: 0000000000000000 [ 85.352175][ T5336] R10: 0000000000df4ca0 R11: 0000000000000246 R12: 0000000000014f26 [ 85.352181][ T5336] R13: 00007f4997a15fac R14: 0000000000014c32 R15: 00007ffddf23d820 [ 85.352191][ T5336] [ 85.578486][ T4661] Bluetooth: hci0: command tx timeout