program: r0 = socket$inet6_tcp(0xa, 0x1, 0x0) r1 = socket$nl_generic(0x10, 0x3, 0x10) r2 = socket$nl_generic(0x10, 0x3, 0x10) r3 = syz_genetlink_get_family_id$smc(&(0x7f00000033c0), r2) sendmsg$SMC_PNETID_ADD(r2, &(0x7f00000034c0)={0x0, 0x0, &(0x7f0000003480)={&(0x7f0000000000)={0x34, r3, 0x1, 0x70bd28, 0x25dfdbfe, {}, [@SMC_PNETID_NAME={0x9, 0x1, 'syz1\x00'}, @SMC_PNETID_ETHNAME={0x14, 0x2, 'bridge_slave_0\x00'}]}, 0x34}, 0x1, 0x0, 0x0, 0x850c081d989709a5}, 0x40000) sendmsg$SMC_PNETID_ADD(r1, &(0x7f0000000180)={0x0, 0x0, &(0x7f0000000100)={&(0x7f0000000040)={0x34, r3, 0x1, 0x70bd2b, 0x25dfdbfd, {}, [@SMC_PNETID_NAME={0x9, 0x1, 'syz2\x00'}, @SMC_PNETID_ETHNAME={0x14, 0x2, 'ip6erspan0\x00'}]}, 0x34}}, 0x800) close(r0) socket(0x2b, 0x1, 0x1) bind$inet6(r0, &(0x7f0000000040)={0xa, 0x4e22, 0x0, @empty}, 0x1c) listen(r0, 0x0) r4 = socket$inet_smc(0x2b, 0x1, 0x0) connect$inet(r4, &(0x7f0000000000)={0x2, 0x4e22, @local}, 0x10) [ 78.987079][ T4656] Bluetooth: hci0: command tx timeout [ 79.059985][ T5325] smc: net device bridge_slave_0 applied user defined pnetid SYZ1 [ 79.139584][ T5324] [ 79.140736][ T5324] ====================================================== [ 79.143707][ T5324] WARNING: possible circular locking dependency detected [ 79.146655][ T5324] syzkaller #0 Not tainted [ 79.148401][ T5324] ------------------------------------------------------ [ 79.151219][ T5324] syz.0.0/5324 is trying to acquire lock: [ 79.153634][ T5324] ffff88800e4e0a68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x100/0xc50 [ 79.158540][ T5324] [ 79.158540][ T5324] but task is already holding lock: [ 79.161773][ T5324] ffff88800e4e0ee0 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x255/0x560 [ 79.165660][ T5324] [ 79.165660][ T5324] which lock already depends on the new lock. [ 79.165660][ T5324] [ 79.169981][ T5324] [ 79.169981][ T5324] the existing dependency chain (in reverse order) is: [ 79.173546][ T5324] [ 79.173546][ T5324] -> #1 (sk_lock-AF_SMC/1){+.+.}-{0:0}: [ 79.176702][ T5324] lock_sock_nested+0x41/0x100 [ 79.178644][ T5324] smc_listen_out+0x109/0x3e0 [ 79.180540][ T5324] smc_listen_work+0x813/0x13f0 [ 79.182707][ T5324] process_scheduled_works+0xb5d/0x1860 [ 79.185248][ T5324] worker_thread+0xa53/0xfc0 [ 79.187399][ T5324] kthread+0x389/0x470 [ 79.189336][ T5324] ret_from_fork+0x514/0xb70 [ 79.191309][ T5324] ret_from_fork_asm+0x1a/0x30 [ 79.193467][ T5324] [ 79.193467][ T5324] -> #0 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}: [ 79.197717][ T5324] __lock_acquire+0x15a5/0x2cf0 [ 79.199960][ T5324] lock_acquire+0x106/0x350 [ 79.202924][ T5324] __flush_work+0x700/0xc50 [ 79.205116][ T5324] __cancel_work_sync+0xbe/0x110 [ 79.207447][ T5324] smc_clcsock_release+0x60/0xf0 [ 79.209878][ T5324] __smc_release+0x66b/0x7e0 [ 79.211993][ T5324] smc_close_non_accepted+0xd5/0x1f0 [ 79.214389][ T5324] smc_close_active+0xb67/0xf10 [ 79.216732][ T5324] __smc_release+0x8d/0x7e0 [ 79.218860][ T5324] smc_release+0x2ce/0x560 [ 79.220976][ T5324] sock_close+0xc3/0x240 [ 79.223046][ T5324] __fput+0x44f/0xa60 [ 79.224986][ T5324] task_work_run+0x1d9/0x270 [ 79.227150][ T5324] exit_to_user_mode_loop+0x193/0x680 [ 79.229560][ T5324] do_syscall_64+0x353/0x580 [ 79.231667][ T5324] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 79.234409][ T5324] [ 79.234409][ T5324] other info that might help us debug this: [ 79.234409][ T5324] [ 79.239062][ T5324] Possible unsafe locking scenario: [ 79.239062][ T5324] [ 79.242197][ T5324] CPU0 CPU1 [ 79.244455][ T5324] ---- ---- [ 79.246607][ T5324] lock(sk_lock-AF_SMC/1); [ 79.248533][ T5324] lock((work_completion)(&new_smc->smc_listen_work)); [ 79.252436][ T5324] lock(sk_lock-AF_SMC/1); [ 79.255417][ T5324] lock((work_completion)(&new_smc->smc_listen_work)); [ 79.258103][ T5324] [ 79.258103][ T5324] *** DEADLOCK *** [ 79.258103][ T5324] [ 79.261315][ T5324] 3 locks held by syz.0.0/5324: [ 79.263277][ T5324] #0: ffff888047da8800 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x9b/0x240 [ 79.267403][ T5324] #1: ffff88800e4e0ee0 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x255/0x560 [ 79.271415][ T5324] #2: ffffffff8e95cd20 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x100/0xc50 [ 79.275237][ T5324] [ 79.275237][ T5324] stack backtrace: [ 79.277914][ T5324] CPU: 0 UID: 0 PID: 5324 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 79.277930][ T5324] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 79.277953][ T5324] Call Trace: [ 79.277987][ T5324] [ 79.278007][ T5324] dump_stack_lvl+0xe8/0x150 [ 79.278022][ T5324] print_circular_bug+0x2e1/0x300 [ 79.278035][ T5324] check_noncircular+0x12e/0x150 [ 79.278048][ T5324] __lock_acquire+0x15a5/0x2cf0 [ 79.278059][ T5324] ? do_raw_spin_lock+0x12b/0x2f0 [ 79.278074][ T5324] ? __flush_work+0x100/0xc50 [ 79.278084][ T5324] lock_acquire+0x106/0x350 [ 79.278094][ T5324] ? __flush_work+0x100/0xc50 [ 79.278105][ T5324] ? __flush_work+0x100/0xc50 [ 79.278115][ T5324] __flush_work+0x700/0xc50 [ 79.278125][ T5324] ? __flush_work+0x100/0xc50 [ 79.278135][ T5324] ? __flush_work+0x100/0xc50 [ 79.278145][ T5324] ? __pfx___flush_work+0x10/0x10 [ 79.278155][ T5324] ? __pfx_wq_barrier_func+0x10/0x10 [ 79.278168][ T5324] ? __cancel_work_sync+0x5c/0x110 [ 79.278179][ T5324] __cancel_work_sync+0xbe/0x110 [ 79.278193][ T5324] smc_clcsock_release+0x60/0xf0 [ 79.278222][ T5324] __smc_release+0x66b/0x7e0 [ 79.278237][ T5324] ? __local_bh_enable_ip+0xd0/0x130 [ 79.278249][ T5324] smc_close_non_accepted+0xd5/0x1f0 [ 79.278265][ T5324] smc_close_active+0xb67/0xf10 [ 79.278278][ T5324] ? __pfx_sock_def_readable+0x10/0x10 [ 79.278290][ T5324] __smc_release+0x8d/0x7e0 [ 79.278302][ T5324] ? __local_bh_enable_ip+0xd0/0x130 [ 79.278313][ T5324] smc_release+0x2ce/0x560 [ 79.278329][ T5324] sock_close+0xc3/0x240 [ 79.278346][ T5324] ? __pfx_sock_close+0x10/0x10 [ 79.278355][ T5324] __fput+0x44f/0xa60 [ 79.278370][ T5324] task_work_run+0x1d9/0x270 [ 79.278386][ T5324] ? __pfx_task_work_run+0x10/0x10 [ 79.278402][ T5324] exit_to_user_mode_loop+0x193/0x680 [ 79.278413][ T5324] ? rcu_is_watching+0x15/0xb0 [ 79.278427][ T5324] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 79.278438][ T5324] do_syscall_64+0x353/0x580 [ 79.278450][ T5324] ? clear_bhb_loop+0x40/0x90 [ 79.278462][ T5324] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 79.278473][ T5324] RIP: 0033:0x7f3c5659ce59 [ 79.278531][ T5324] 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 [ 79.278541][ T5324] RSP: 002b:00007ffd8cc1ac28 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 [ 79.278553][ T5324] RAX: 0000000000000000 RBX: 00007f3c56817da0 RCX: 00007f3c5659ce59 [ 79.278561][ T5324] RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 [ 79.278567][ T5324] RBP: 00007f3c56817da0 R08: 00007f3c56816038 R09: 0000000000000000 [ 79.278574][ T5324] R10: 0000000000df35c0 R11: 0000000000000246 R12: 000000000001375e [ 79.278581][ T5324] R13: 00007f3c56815fac R14: 0000000000013482 R15: 00007ffd8cc1ad30 [ 79.278593][ T5324]