====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.0.2774/16251 is trying to acquire lock: ffff88805269d570 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] ffff88805269d570 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] ffff88805269d570 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4354 [inline] ffff88805269d570 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x101/0xca0 kernel/workqueue.c:4412 but task is already holding lock: ffff88805269d9e0 (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:3865 smc_listen_out+0xd4/0x3d0 net/smc/af_smc.c:1934 smc_listen_work+0x81d/0x1410 net/smc/af_smc.c:-1 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 kthread+0x38b/0x480 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:3209 [inline] check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 touch_work_lockdep_map kernel/workqueue.c:4126 [inline] start_flush_work kernel/workqueue.c:4380 [inline] __flush_work+0x74c/0xca0 kernel/workqueue.c:4412 __cancel_work_sync kernel/workqueue.c:4568 [inline] cancel_work_sync+0xb8/0xf0 kernel/workqueue.c:4605 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+0xb30/0xf20 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+0xa0/0x1f0 net/socket.c:735 sock_close+0x1c/0x30 net/socket.c:1526 __fput+0x408/0xa40 fs/file_table.c:512 fput_close_sync+0x11f/0x240 fs/file_table.c:618 filp_close_sync+0x6e/0xa0 fs/open.c:1573 close_files fs/file.c:572 [inline] put_files_struct+0x230/0x3c0 fs/file.c:584 do_exit+0x6f0/0x2360 kernel/exit.c:977 do_group_exit+0x22d/0x2f0 kernel/exit.c:1123 get_signal+0x1216/0x12c0 kernel/signal.c:3112 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101 __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:343 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 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 *** locks held by syz.0.2774/16251: 3, last CPU#1: #0: ffff888076df9380 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #0: ffff888076df9380 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x7a/0x1f0 net/socket.c:734 #1: ffff88805269d9e0 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x24d/0x550 net/smc/af_smc.c:-1 #2: ffffffff8fd58a60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #2: ffffffff8fd58a60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8fd58a60 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4354 [inline] #2: ffffffff8fd58a60 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x101/0xca0 kernel/workqueue.c:4412 stack backtrace: CPU: 1 UID: 0 PID: 16251 Comm: syz.0.2774 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2087 check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2219 check_prev_add kernel/locking/lockdep.c:3209 [inline] check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 touch_work_lockdep_map kernel/workqueue.c:4126 [inline] start_flush_work kernel/workqueue.c:4380 [inline] __flush_work+0x74c/0xca0 kernel/workqueue.c:4412 __cancel_work_sync kernel/workqueue.c:4568 [inline] cancel_work_sync+0xb8/0xf0 kernel/workqueue.c:4605 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+0xb30/0xf20 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+0xa0/0x1f0 net/socket.c:735 sock_close+0x1c/0x30 net/socket.c:1526 __fput+0x408/0xa40 fs/file_table.c:512 fput_close_sync+0x11f/0x240 fs/file_table.c:618 filp_close_sync+0x6e/0xa0 fs/open.c:1573 close_files fs/file.c:572 [inline] put_files_struct+0x230/0x3c0 fs/file.c:584 do_exit+0x6f0/0x2360 kernel/exit.c:977 do_group_exit+0x22d/0x2f0 kernel/exit.c:1123 get_signal+0x1216/0x12c0 kernel/signal.c:3112 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101 __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:343 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f609699f559 Code: Unable to access opcode bytes at 0x7f609699f52f. RSP: 002b:00007f60978b20e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f6096c25fa8 RCX: 00007f609699f559 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f6096c25fa8 RBP: 00007f6096c25fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6096c26038 R14: 00007f6096d4f960 R15: 00007f6096d4fa48