====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.17/6113 is trying to acquire lock: ffff88803bfe2b70 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] ffff88803bfe2b70 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] ffff88803bfe2b70 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4284 [inline] ffff88803bfe2b70 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x104/0xda0 kernel/workqueue.c:4342 but task is already holding lock: ffff88803bfe3118 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x24d/0x5a0 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+0x41/0x130 net/core/sock.c:3783 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:3308 [inline] process_scheduled_works+0xb68/0x1910 kernel/workqueue.c:3399 worker_thread+0xa90/0x1040 kernel/workqueue.c:3485 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:3167 [inline] check_prevs_add kernel/locking/lockdep.c:3286 [inline] validate_chain kernel/locking/lockdep.c:3910 [inline] __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5239 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5870 touch_work_lockdep_map kernel/workqueue.c:4056 [inline] start_flush_work kernel/workqueue.c:4310 [inline] __flush_work+0x6df/0xda0 kernel/workqueue.c:4342 __cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4498 smc_clcsock_release+0x60/0xf0 net/smc/smc_close.c:29 __smc_release+0x6a0/0x810 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+0xb9b/0xf40 net/smc/smc_close.c:225 __smc_release+0xa0/0x810 net/smc/af_smc.c:292 smc_release+0x2eb/0x5a0 net/smc/af_smc.c:359 __sock_release net/socket.c:722 [inline] sock_close+0xc3/0x240 net/socket.c:1514 __fput+0x461/0xa70 fs/file_table.c:510 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 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:238 [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.0.17/6113: #0: ffff888043f72b38 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline] #0: ffff888043f72b38 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:721 [inline] #0: ffff888043f72b38 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1514 #1: ffff88803bfe3118 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x24d/0x5a0 net/smc/af_smc.c:-1 #2: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #2: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4284 [inline] #2: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x104/0xda0 kernel/workqueue.c:4342 stack backtrace: CPU: 1 UID: 0 PID: 6113 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 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:2045 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2177 check_prev_add kernel/locking/lockdep.c:3167 [inline] check_prevs_add kernel/locking/lockdep.c:3286 [inline] validate_chain kernel/locking/lockdep.c:3910 [inline] __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5239 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5870 touch_work_lockdep_map kernel/workqueue.c:4056 [inline] start_flush_work kernel/workqueue.c:4310 [inline] __flush_work+0x6df/0xda0 kernel/workqueue.c:4342 __cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4498 smc_clcsock_release+0x60/0xf0 net/smc/smc_close.c:29 __smc_release+0x6a0/0x810 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+0xb9b/0xf40 net/smc/smc_close.c:225 __smc_release+0xa0/0x810 net/smc/af_smc.c:292 smc_release+0x2eb/0x5a0 net/smc/af_smc.c:359 __sock_release net/socket.c:722 [inline] sock_close+0xc3/0x240 net/socket.c:1514 __fput+0x461/0xa70 fs/file_table.c:510 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 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:238 [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: 0033:0x7f7e6b74c819 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 RSP: 002b:00007ffff6858368 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007ffff6858450 RCX: 00007f7e6b74c819 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00000000000209a4 R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b33720000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7e6b9c5fac R14: 00007f7e6b9c5fa8 R15: 00007f7e6b9c5fa0