====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.73/4729 is trying to acquire lock: ffff88805a090910 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0xc1/0x1b0 kernel/workqueue.c:3090 but task is already holding lock: ffff88801da30120 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x251/0x530 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+0x44/0x100 net/core/sock.c:3251 smc_listen_out+0x109/0x3d0 net/smc/af_smc.c:1524 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 -> #0 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __flush_work+0xdd/0x1b0 kernel/workqueue.c:3090 __cancel_work_timer+0x3ac/0x520 kernel/workqueue.c:3181 smc_clcsock_release+0x5c/0xe0 net/smc/smc_close.c:29 __smc_release+0x398/0x500 net/smc/af_smc.c:211 smc_close_non_accepted+0xd1/0x1f0 net/smc/af_smc.c:1466 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline] smc_close_active+0x9d3/0xd90 net/smc/smc_close.c:219 __smc_release+0x9a/0x500 net/smc/af_smc.c:187 smc_release+0x2ca/0x530 net/smc/af_smc.c:254 __sock_release net/socket.c:649 [inline] sock_close+0xd5/0x240 net/socket.c:1336 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x61e/0x20a0 kernel/exit.c:883 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:280 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 *** 2 locks held by syz.0.73/4729: #0: ffff8880616f8210 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #0: ffff8880616f8210 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:648 [inline] #0: ffff8880616f8210 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1336 #1: ffff88801da30120 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x251/0x530 net/smc/af_smc.c:-1 stack backtrace: CPU: 1 PID: 4729 Comm: syz.0.73 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __flush_work+0xdd/0x1b0 kernel/workqueue.c:3090 __cancel_work_timer+0x3ac/0x520 kernel/workqueue.c:3181 smc_clcsock_release+0x5c/0xe0 net/smc/smc_close.c:29 __smc_release+0x398/0x500 net/smc/af_smc.c:211 smc_close_non_accepted+0xd1/0x1f0 net/smc/af_smc.c:1466 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline] smc_close_active+0x9d3/0xd90 net/smc/smc_close.c:219 __smc_release+0x9a/0x500 net/smc/af_smc.c:187 smc_release+0x2ca/0x530 net/smc/af_smc.c:254 __sock_release net/socket.c:649 [inline] sock_close+0xd5/0x240 net/socket.c:1336 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x61e/0x20a0 kernel/exit.c:883 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:280 RIP: 0033:0x7f1636aaf449 Code: Unable to access opcode bytes at RIP 0x7f1636aaf41f. RSP: 002b:00007f1634ca01c0 EFLAGS: 00000206 ORIG_RAX: 00000000000001b3 RAX: 0000000000000000 RBX: 00007f1636a31830 RCX: 00007f1636aaf449 RDX: 00007f1636a31830 RSI: 0000000000000058 RDI: 00007ffcb346e450 RBP: 00007f1634ca06c0 R08: 00007f1634ca06c0 R09: 00007ffcb346e537 R10: 0000000000000008 R11: 0000000000000206 R12: ffffffffffffffa8 R13: 000000000000000b R14: 00007ffcb346e450 R15: 00007ffcb346e538