====================================================== WARNING: possible circular locking dependency detected 6.15.0-syzkaller-13659-g5b032cac6225 #0 Not tainted ------------------------------------------------------ syz.4.5248/29937 is trying to acquire lock: ffff888063cf8958 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] ffff888063cf8958 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] ffff888063cf8958 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4152 [inline] ffff888063cf8958 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0xd2/0xbc0 kernel/workqueue.c:4210 but task is already holding lock: ffff888063cf9958 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x255/0x540 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_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 lock_sock_nested+0x48/0x100 net/core/sock.c:3752 smc_listen_out+0x109/0x3e0 net/smc/af_smc.c:1913 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 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:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3911 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 touch_work_lockdep_map kernel/workqueue.c:3924 [inline] start_flush_work kernel/workqueue.c:4178 [inline] __flush_work+0x6b8/0xbc0 kernel/workqueue.c:4210 __cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4366 smc_clcsock_release+0x60/0xf0 net/smc/smc_close.c:29 __smc_release+0x66b/0x7e0 net/smc/af_smc.c:301 smc_close_non_accepted+0xd5/0x1f0 net/smc/af_smc.c:1844 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline] smc_close_active+0xb68/0xf10 net/smc/smc_close.c:225 __smc_release+0x8d/0x7e0 net/smc/af_smc.c:277 smc_release+0x2ce/0x540 net/smc/af_smc.c:344 __sock_release net/socket.c:647 [inline] sock_close+0xc3/0x240 net/socket.c:1391 __fput+0x44c/0xa70 fs/file_table.c:465 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] __do_fast_syscall_32+0x1f4/0x2b0 arch/x86/entry/syscall_32.c:309 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e 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.4.5248/29937: #0: ffff88805797e808 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #0: ffff88805797e808 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:646 [inline] #0: ffff88805797e808 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1391 #1: ffff888063cf9958 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x255/0x540 net/smc/af_smc.c:-1 #2: ffffffff8e13f060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #2: ffffffff8e13f060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #2: ffffffff8e13f060 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4152 [inline] #2: ffffffff8e13f060 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xd2/0xbc0 kernel/workqueue.c:4210 stack backtrace: CPU: 0 UID: 0 PID: 29937 Comm: syz.4.5248 Not tainted 6.15.0-syzkaller-13659-g5b032cac6225 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2046 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3911 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 touch_work_lockdep_map kernel/workqueue.c:3924 [inline] start_flush_work kernel/workqueue.c:4178 [inline] __flush_work+0x6b8/0xbc0 kernel/workqueue.c:4210 __cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4366 smc_clcsock_release+0x60/0xf0 net/smc/smc_close.c:29 __smc_release+0x66b/0x7e0 net/smc/af_smc.c:301 smc_close_non_accepted+0xd5/0x1f0 net/smc/af_smc.c:1844 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline] smc_close_active+0xb68/0xf10 net/smc/smc_close.c:225 __smc_release+0x8d/0x7e0 net/smc/af_smc.c:277 smc_release+0x2ce/0x540 net/smc/af_smc.c:344 __sock_release net/socket.c:647 [inline] sock_close+0xc3/0x240 net/socket.c:1391 __fput+0x44c/0xa70 fs/file_table.c:465 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] __do_fast_syscall_32+0x1f4/0x2b0 arch/x86/entry/syscall_32.c:309 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf709e539 Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f508e55c EFLAGS: 00000206 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00000000ffffffff RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 4: 10 07 adc %al,(%rdi) 6: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi a: 10 08 adc %cl,(%rax) c: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 20: 00 51 52 add %dl,0x52(%rcx) 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 ret 2e: 90 nop 2f: 90 nop 30: 90 nop 31: 90 nop 32: 90 nop 33: 90 nop 34: 90 nop 35: 90 nop 36: 90 nop 37: 90 nop 38: 90 nop 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop