====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.1.3609/20467 is trying to acquire lock: ffff88805acae1e8 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] ffff88805acae1e8 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] ffff88805acae1e8 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4272 [inline] ffff88805acae1e8 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x101/0xca0 kernel/workqueue.c:4330 but task is already holding lock: ffff88805acacd60 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x24d/0x550 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:3825 smc_listen_out+0x105/0x3c0 net/smc/af_smc.c:1935 smc_listen_work+0x81d/0x1410 net/smc/af_smc.c:-1 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3397 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3478 kthread+0x389/0x470 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+0x1520/0x2cd0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 touch_work_lockdep_map kernel/workqueue.c:4044 [inline] start_flush_work kernel/workqueue.c:4298 [inline] __flush_work+0x74c/0xca0 kernel/workqueue.c:4330 __cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4486 smc_clcsock_release+0x60/0xf0 net/smc/smc_close.c:29 __smc_release+0x64e/0x7c0 net/smc/af_smc.c:318 smc_close_non_accepted+0xd5/0x1f0 net/smc/af_smc.c:1866 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline] smc_close_active+0xb42/0xf30 net/smc/smc_close.c:225 __smc_release+0x9c/0x7c0 net/smc/af_smc.c:294 smc_release+0x2c5/0x550 net/smc/af_smc.c:361 __sock_release net/socket.c:722 [inline] sock_close+0xad/0x220 net/socket.c:1515 __fput+0x418/0xa50 fs/file_table.c:510 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x73a/0x2360 kernel/exit.c:976 do_group_exit+0x22d/0x2f0 kernel/exit.c:1119 get_signal+0x121b/0x12c0 kernel/signal.c:3038 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0xa9/0x6b0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 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.1.3609/20467: #0: ffff88805c6ccd00 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline] #0: ffff88805c6ccd00 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:721 [inline] #0: ffff88805c6ccd00 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x82/0x220 net/socket.c:1515 #1: ffff88805acacd60 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x24d/0x550 net/smc/af_smc.c:-1 #2: ffffffff8e95c780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #2: ffffffff8e95c780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8e95c780 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4272 [inline] #2: ffffffff8e95c780 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x101/0xca0 kernel/workqueue.c:4330 stack backtrace: CPU: 0 UID: 0 PID: 20467 Comm: syz.1.3609 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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+0x1520/0x2cd0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 touch_work_lockdep_map kernel/workqueue.c:4044 [inline] start_flush_work kernel/workqueue.c:4298 [inline] __flush_work+0x74c/0xca0 kernel/workqueue.c:4330 __cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4486 smc_clcsock_release+0x60/0xf0 net/smc/smc_close.c:29 __smc_release+0x64e/0x7c0 net/smc/af_smc.c:318 smc_close_non_accepted+0xd5/0x1f0 net/smc/af_smc.c:1866 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline] smc_close_active+0xb42/0xf30 net/smc/smc_close.c:225 __smc_release+0x9c/0x7c0 net/smc/af_smc.c:294 smc_release+0x2c5/0x550 net/smc/af_smc.c:361 __sock_release net/socket.c:722 [inline] sock_close+0xad/0x220 net/socket.c:1515 __fput+0x418/0xa50 fs/file_table.c:510 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x73a/0x2360 kernel/exit.c:976 do_group_exit+0x22d/0x2f0 kernel/exit.c:1119 get_signal+0x121b/0x12c0 kernel/signal.c:3038 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0xa9/0x6b0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa8be79ce59 Code: Unable to access opcode bytes at 0x7fa8be79ce2f. RSP: 002b:00007fa8bf6ae0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007fa8bea15fa8 RCX: 00007fa8be79ce59 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fa8bea15fac RBP: 00007fa8bea15fa0 R08: 3fffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa8bea16038 R14: 00007ffc2f7612d0 R15: 00007ffc2f7613b8