====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.0.1086/11966 is trying to acquire lock: ffff8880826b8a68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] ffff8880826b8a68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] ffff8880826b8a68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4260 [inline] ffff8880826b8a68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x100/0xc50 kernel/workqueue.c:4318 but task is already holding lock: ffff8880826b8ee0 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x255/0x560 net/smc/af_smc.c:-1 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (sk_lock-AF_SMC/1){+.+.}-{0:0}: lock_sock_nested+0x41/0x100 net/core/sock.c:3780 smc_listen_out+0x109/0x3e0 net/smc/af_smc.c:1936 smc_listen_work+0x813/0x13f0 net/smc/af_smc.c:-1 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #0 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 touch_work_lockdep_map kernel/workqueue.c:4032 [inline] start_flush_work kernel/workqueue.c:4286 [inline] __flush_work+0x700/0xc50 kernel/workqueue.c:4318 __cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4474 smc_clcsock_release+0x60/0xf0 net/smc/smc_close.c:29 __smc_release+0x66b/0x7e0 net/smc/af_smc.c:316 smc_close_non_accepted+0xd5/0x1f0 net/smc/af_smc.c:1867 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline] smc_close_active+0xb67/0xf10 net/smc/smc_close.c:225 __smc_release+0x8d/0x7e0 net/smc/af_smc.c:292 smc_release+0x2ce/0x560 net/smc/af_smc.c:359 __sock_release net/socket.c:721 [inline] sock_close+0xc3/0x240 net/socket.c:1513 __fput+0x44f/0xa60 fs/file_table.c:473 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x70f/0x22c0 kernel/exit.c:975 do_group_exit+0x21b/0x2d0 kernel/exit.c:1117 get_signal+0x1284/0x1330 kernel/signal.c:3037 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sk_lock-AF_SMC/1); lock((work_completion)(&new_smc->smc_listen_work)); lock(sk_lock-AF_SMC/1); lock((work_completion)(&new_smc->smc_listen_work)); *** DEADLOCK *** 3 locks held by syz.0.1086/11966: #0: ffff888059f7fa40 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline] #0: ffff888059f7fa40 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:720 [inline] #0: ffff888059f7fa40 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1513 #1: ffff8880826b8ee0 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x255/0x560 net/smc/af_smc.c:-1 #2: ffffffff8e95d260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #2: ffffffff8e95d260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #2: ffffffff8e95d260 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4260 [inline] #2: ffffffff8e95d260 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x100/0xc50 kernel/workqueue.c:4318 stack backtrace: CPU: 1 UID: 0 PID: 11966 Comm: syz.0.1086 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 touch_work_lockdep_map kernel/workqueue.c:4032 [inline] start_flush_work kernel/workqueue.c:4286 [inline] __flush_work+0x700/0xc50 kernel/workqueue.c:4318 __cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4474 smc_clcsock_release+0x60/0xf0 net/smc/smc_close.c:29 __smc_release+0x66b/0x7e0 net/smc/af_smc.c:316 smc_close_non_accepted+0xd5/0x1f0 net/smc/af_smc.c:1867 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline] smc_close_active+0xb67/0xf10 net/smc/smc_close.c:225 __smc_release+0x8d/0x7e0 net/smc/af_smc.c:292 smc_release+0x2ce/0x560 net/smc/af_smc.c:359 __sock_release net/socket.c:721 [inline] sock_close+0xc3/0x240 net/socket.c:1513 __fput+0x44f/0xa60 fs/file_table.c:473 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x70f/0x22c0 kernel/exit.c:975 do_group_exit+0x21b/0x2d0 kernel/exit.c:1117 get_signal+0x1284/0x1330 kernel/signal.c:3037 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fadb839c819 Code: Unable to access opcode bytes at 0x7fadb839c7ef. RSP: 002b:00007fadb92a1028 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: fffffffffffffffc RBX: 00007fadb8616090 RCX: 00007fadb839c819 RDX: 0000000000000010 RSI: 0000200000000000 RDI: 0000000000000006 RBP: 00007fadb8432c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fadb8616128 R14: 00007fadb8616090 R15: 00007ffe3ff4ca68