====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.1020/8982 is trying to acquire lock: ffff88807b4db618 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] ffff88807b4db618 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] ffff88807b4db618 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:3416 [inline] ffff88807b4db618 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x120/0xac0 kernel/workqueue.c:3474 but task is already holding lock: ffff88807b4d97b0 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x24d/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+0x48/0x100 net/core/sock.c:3543 smc_listen_out+0xd4/0x3c0 net/smc/af_smc.c:1926 smc_listen_out_connected net/smc/af_smc.c:1948 [inline] smc_listen_decline net/smc/af_smc.c:1983 [inline] smc_listen_work+0x580/0xf40 net/smc/af_smc.c:2580 process_one_work kernel/workqueue.c:2657 [inline] process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 -> #0 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3162 [inline] check_prevs_add kernel/locking/lockdep.c:3281 [inline] validate_chain kernel/locking/lockdep.c:3897 [inline] __lock_acquire+0x3a07/0x7eb0 kernel/locking/lockdep.c:5171 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5790 touch_work_lockdep_map kernel/workqueue.c:3190 [inline] start_flush_work kernel/workqueue.c:3442 [inline] __flush_work+0x66e/0xac0 kernel/workqueue.c:3474 __cancel_work_timer+0x3f8/0x560 kernel/workqueue.c:3562 smc_clcsock_release+0x60/0xf0 net/smc/smc_close.c:29 __smc_release+0x644/0x7b0 net/smc/af_smc.c:315 smc_close_non_accepted+0xd5/0x1f0 net/smc/af_smc.c:1858 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline] smc_close_active+0xb3b/0xf20 net/smc/smc_close.c:225 __smc_release+0x9c/0x7b0 net/smc/af_smc.c:291 smc_release+0x2c5/0x530 net/smc/af_smc.c:358 __sock_release net/socket.c:659 [inline] sock_close+0xa7/0x210 net/socket.c:1421 __fput+0x221/0x940 fs/file_table.c:418 task_work_run+0x1d4/0x260 kernel/task_work.c:245 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:180 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213 __syscall_exit_to_user_mode_work kernel/entry/common.c:294 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:305 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 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.0.1020/8982: #0: ffff88805b515c20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #0: ffff88805b515c20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline] #0: ffff88805b515c20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x82/0x210 net/socket.c:1421 #1: ffff88807b4d97b0 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x24d/0x530 net/smc/af_smc.c:-1 #2: ffffffff8df320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #2: ffffffff8df320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #2: ffffffff8df320e0 (rcu_read_lock){....}-{1:2}, at: start_flush_work kernel/workqueue.c:3416 [inline] #2: ffffffff8df320e0 (rcu_read_lock){....}-{1:2}, at: __flush_work+0x120/0xac0 kernel/workqueue.c:3474 stack backtrace: CPU: 1 PID: 8982 Comm: syz.0.1020 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2215 check_prev_add kernel/locking/lockdep.c:3162 [inline] check_prevs_add kernel/locking/lockdep.c:3281 [inline] validate_chain kernel/locking/lockdep.c:3897 [inline] __lock_acquire+0x3a07/0x7eb0 kernel/locking/lockdep.c:5171 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5790 touch_work_lockdep_map kernel/workqueue.c:3190 [inline] start_flush_work kernel/workqueue.c:3442 [inline] __flush_work+0x66e/0xac0 kernel/workqueue.c:3474 __cancel_work_timer+0x3f8/0x560 kernel/workqueue.c:3562 smc_clcsock_release+0x60/0xf0 net/smc/smc_close.c:29 __smc_release+0x644/0x7b0 net/smc/af_smc.c:315 smc_close_non_accepted+0xd5/0x1f0 net/smc/af_smc.c:1858 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline] smc_close_active+0xb3b/0xf20 net/smc/smc_close.c:225 __smc_release+0x9c/0x7b0 net/smc/af_smc.c:291 smc_release+0x2c5/0x530 net/smc/af_smc.c:358 __sock_release net/socket.c:659 [inline] sock_close+0xa7/0x210 net/socket.c:1421 __fput+0x221/0x940 fs/file_table.c:418 task_work_run+0x1d4/0x260 kernel/task_work.c:245 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:180 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213 __syscall_exit_to_user_mode_work kernel/entry/common.c:294 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:305 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f99f379e559 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:00007ffdc49f0e48 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007ffdc49f0f30 RCX: 00007f99f379e559 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00000000000633b2 R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b2c720000 R11: 0000000000000246 R12: 00007ffdc49f0f70 R13: 00007f99f3a25fac R14: 00000000000633f8 R15: 00007f99f3a25fa0