program: r0 = socket$inet6_tcp(0xa, 0x1, 0x0) close(r0) socket(0x2b, 0x1, 0x1) r1 = socket$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) bind$inet6(r0, &(0x7f0000000040)={0xa, 0x4e22, 0x0, @empty}, 0x1c) ioctl$KVM_GET_CLOCK(r0, 0x8030ae7c, &(0x7f00000002c0)) r4 = syz_genetlink_get_family_id$mptcp(&(0x7f00000000c0), r1) ioctl$ifreq_SIOCGIFINDEX_team(r1, 0x8933, &(0x7f0000000140)={'team0\x00', 0x0}) sendmsg$MPTCP_PM_CMD_GET_LIMITS(0xffffffffffffffff, &(0x7f0000000280)={&(0x7f0000000080)={0x10, 0x0, 0x0, 0x100}, 0xc, &(0x7f0000000240)={&(0x7f00000001c0)={0x70, r4, 0x20, 0x70bd25, 0x25dfdbfd, {}, [@MPTCP_PM_ATTR_RCV_ADD_ADDRS={0x8, 0x2, 0x4}, @MPTCP_PM_ATTR_ADDR_REMOTE={0x14, 0x6, 0x0, 0x1, [@MPTCP_PM_ADDR_ATTR_PORT={0x6, 0x5, 0x4e24}, @MPTCP_PM_ADDR_ATTR_ADDR4={0x8, 0x3, @initdev={0xac, 0x1e, 0x0, 0x0}}]}, @MPTCP_PM_ATTR_ADDR={0x1c, 0x1, 0x0, 0x1, [@MPTCP_PM_ADDR_ATTR_FLAGS={0x8}, @MPTCP_PM_ADDR_ATTR_IF_IDX={0x8, 0x7, r5}, @MPTCP_PM_ADDR_ATTR_ID={0x5, 0x2, 0x5}]}, @MPTCP_PM_ATTR_ADDR_REMOTE={0xc, 0x6, 0x0, 0x1, [@MPTCP_PM_ADDR_ATTR_FAMILY={0x6, 0x1, 0xa}]}, @MPTCP_PM_ATTR_SUBFLOWS={0x8, 0x3, 0x8}, @MPTCP_PM_ATTR_RCV_ADD_ADDRS={0x8, 0x2, 0x1}, @MPTCP_PM_ATTR_TOKEN={0x8, 0x4, 0x1}]}, 0x70}, 0x1, 0x0, 0x0, 0x4000000}, 0x20000000) listen(r0, 0xffffffff) r6 = socket$inet_smc(0x2b, 0x1, 0x0) connect$inet(r6, &(0x7f0000000000)={0x2, 0x4e22, @local}, 0x10) [ 94.758502][ T5276] Bluetooth: hci0: command tx timeout [ 94.849214][ T5316] smc: net device bridge_slave_0 applied user defined pnetid SYZ1 [ 94.956317][ T5315] [ 94.957356][ T5315] ====================================================== [ 94.960385][ T5315] WARNING: possible circular locking dependency detected [ 94.963227][ T5315] syzkaller #0 Not tainted [ 94.965009][ T5315] ------------------------------------------------------ [ 94.967768][ T5315] syz.0.0/5315 is trying to acquire lock: [ 94.970141][ T5315] ffff888037810a68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x101/0xca0 [ 94.975068][ T5315] [ 94.975068][ T5315] but task is already holding lock: [ 94.978232][ T5315] ffff888037810ee0 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x24d/0x550 [ 94.982023][ T5315] [ 94.982023][ T5315] which lock already depends on the new lock. [ 94.982023][ T5315] [ 94.986233][ T5315] [ 94.986233][ T5315] the existing dependency chain (in reverse order) is: [ 94.989725][ T5315] [ 94.989725][ T5315] -> #1 (sk_lock-AF_SMC/1){+.+.}-{0:0}: [ 94.992896][ T5315] lock_sock_nested+0x41/0x100 [ 94.995305][ T5315] smc_listen_out+0xd4/0x3d0 [ 94.997646][ T5315] smc_listen_work+0x81d/0x1410 [ 95.000014][ T5315] process_scheduled_works+0xa8e/0x14e0 [ 95.002749][ T5315] worker_thread+0xa47/0xfb0 [ 95.004872][ T5315] kthread+0x388/0x470 [ 95.006753][ T5315] ret_from_fork+0x514/0xb70 [ 95.008876][ T5315] ret_from_fork_asm+0x1a/0x30 [ 95.011194][ T5315] [ 95.011194][ T5315] -> #0 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}: [ 95.015194][ T5315] __lock_acquire+0x1520/0x2cf0 [ 95.017314][ T5315] lock_acquire+0x106/0x350 [ 95.019449][ T5315] __flush_work+0x74c/0xca0 [ 95.021541][ T5315] __cancel_work_sync+0xbe/0x110 [ 95.023904][ T5315] smc_clcsock_release+0x60/0xf0 [ 95.026127][ T5315] __smc_release+0x64e/0x7c0 [ 95.028391][ T5315] smc_close_non_accepted+0xd5/0x1f0 [ 95.030790][ T5315] smc_close_active+0xb42/0xf30 [ 95.032854][ T5315] __smc_release+0x9c/0x7c0 [ 95.034817][ T5315] smc_release+0x2c5/0x550 [ 95.037042][ T5315] sock_close+0xad/0x220 [ 95.038963][ T5315] __fput+0x418/0xa50 [ 95.040609][ T5315] task_work_run+0x1d9/0x270 [ 95.042721][ T5315] exit_to_user_mode_loop+0x1fa/0x730 [ 95.045005][ T5315] do_syscall_64+0x353/0x580 [ 95.046982][ T5315] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 95.049573][ T5315] [ 95.049573][ T5315] other info that might help us debug this: [ 95.049573][ T5315] [ 95.053810][ T5315] Possible unsafe locking scenario: [ 95.053810][ T5315] [ 95.056927][ T5315] CPU0 CPU1 [ 95.059363][ T5315] ---- ---- [ 95.062098][ T5315] lock(sk_lock-AF_SMC/1); [ 95.064059][ T5315] lock((work_completion)(&new_smc->smc_listen_work)); [ 95.067959][ T5315] lock(sk_lock-AF_SMC/1); [ 95.071485][ T5315] lock((work_completion)(&new_smc->smc_listen_work)); [ 95.075376][ T5315] [ 95.075376][ T5315] *** DEADLOCK *** [ 95.075376][ T5315] [ 95.079711][ T5315] 3 locks held by syz.0.0/5315: [ 95.082670][ T5315] #0: ffff888013052a80 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x82/0x220 [ 95.087059][ T5315] #1: ffff888037810ee0 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x24d/0x550 [ 95.091412][ T5315] #2: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x101/0xca0 [ 95.096796][ T5315] [ 95.096796][ T5315] stack backtrace: [ 95.100358][ T5315] CPU: 0 UID: 0 PID: 5315 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 95.100379][ T5315] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 95.100388][ T5315] Call Trace: [ 95.100397][ T5315] [ 95.100403][ T5315] dump_stack_lvl+0xe8/0x150 [ 95.100430][ T5315] print_circular_bug+0x2e1/0x300 [ 95.100449][ T5315] check_noncircular+0x12e/0x150 [ 95.100470][ T5315] __lock_acquire+0x1520/0x2cf0 [ 95.100489][ T5315] ? do_raw_spin_unlock+0x4d/0x210 [ 95.100512][ T5315] ? __flush_work+0x101/0xca0 [ 95.100524][ T5315] lock_acquire+0x106/0x350 [ 95.100537][ T5315] ? __flush_work+0x101/0xca0 [ 95.100551][ T5315] ? __flush_work+0x101/0xca0 [ 95.100563][ T5315] __flush_work+0x74c/0xca0 [ 95.100575][ T5315] ? __flush_work+0x101/0xca0 [ 95.100587][ T5315] ? __flush_work+0x101/0xca0 [ 95.100599][ T5315] ? __pfx___flush_work+0x10/0x10 [ 95.100616][ T5315] ? __pfx_wq_barrier_func+0x10/0x10 [ 95.100632][ T5315] ? __cancel_work_sync+0x5c/0x110 [ 95.100646][ T5315] __cancel_work_sync+0xbe/0x110 [ 95.100659][ T5315] smc_clcsock_release+0x60/0xf0 [ 95.100676][ T5315] __smc_release+0x64e/0x7c0 [ 95.100690][ T5315] smc_close_non_accepted+0xd5/0x1f0 [ 95.100704][ T5315] smc_close_active+0xb42/0xf30 [ 95.100717][ T5315] ? __pfx_sock_def_readable+0x10/0x10 [ 95.100732][ T5315] __smc_release+0x9c/0x7c0 [ 95.100744][ T5315] ? __local_bh_enable_ip+0xd0/0x130 [ 95.100757][ T5315] smc_release+0x2c5/0x550 [ 95.100768][ T5315] sock_close+0xad/0x220 [ 95.100781][ T5315] ? __pfx_sock_close+0x10/0x10 [ 95.100792][ T5315] __fput+0x418/0xa50 [ 95.100807][ T5315] task_work_run+0x1d9/0x270 [ 95.100824][ T5315] ? __pfx_task_work_run+0x10/0x10 [ 95.100841][ T5315] exit_to_user_mode_loop+0x1fa/0x730 [ 95.100856][ T5315] ? rcu_is_watching+0x15/0xb0 [ 95.100873][ T5315] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 95.100884][ T5315] do_syscall_64+0x353/0x580 [ 95.100900][ T5315] ? clear_bhb_loop+0x70/0xc0 [ 95.100913][ T5315] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 95.100924][ T5315] RIP: 0033:0x7f47f359e0d9 [ 95.100937][ T5315] 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 [ 95.100947][ T5315] RSP: 002b:00007fff0a1f4e18 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 [ 95.100961][ T5315] RAX: 0000000000000000 RBX: 00007fff0a1f4f00 RCX: 00007f47f359e0d9 [ 95.100969][ T5315] RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 [ 95.100976][ T5315] RBP: 00000000000171bd R08: 0000000000000001 R09: 0000000000000000 [ 95.100983][ T5315] R10: 00007f47f33ff02c R11: 0000000000000246 R12: 00007fff0a1f4f40 [ 95.100991][ T5315] R13: 00007f47f3825fac R14: 0000000000017234 R15: 00007f47f3825fa0 [ 95.101001][ T5315]