====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L Y ------------------------------------------------------ syz.0.2076/12953 is trying to acquire lock: ffff88806e7dee70 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: touch_work_lockdep_map kernel/workqueue.c:4287 [inline] ffff88806e7dee70 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4541 [inline] ffff88806e7dee70 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x539/0xd20 kernel/workqueue.c:4573 but task is already holding lock: ffff88806c1c0260 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x3a5/0x620 net/smc/af_smc.c:353 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 kernel/locking/lockdep.c:5942 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899 lock_sock_nested+0x41/0xf0 net/core/sock.c:3908 smc_listen_out+0xf2/0x4b0 net/smc/af_smc.c:1940 smc_listen_out_connected net/smc/af_smc.c:1962 [inline] smc_listen_decline net/smc/af_smc.c:1997 [inline] smc_listen_work+0x4c2/0x52e0 net/smc/af_smc.c:2594 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495 process_scheduled_works kernel/workqueue.c:3578 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 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+0xeb/0xe60 kernel/locking/lockdep.c:3209 check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x1528/0x1f40 kernel/locking/lockdep.c:5288 lock_acquire kernel/locking/lockdep.c:5942 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899 touch_work_lockdep_map kernel/workqueue.c:4287 [inline] start_flush_work kernel/workqueue.c:4541 [inline] __flush_work+0x54d/0xd20 kernel/workqueue.c:4573 __cancel_work_sync kernel/workqueue.c:4729 [inline] cancel_work_sync+0xcc/0xf0 kernel/workqueue.c:4766 smc_clcsock_release+0x5f/0xe0 net/smc/smc_close.c:29 __smc_release+0x5c2/0x880 net/smc/af_smc.c:318 smc_close_non_accepted+0xda/0x200 net/smc/af_smc.c:1870 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline] smc_close_active+0x4ff/0x11a0 net/smc/smc_close.c:226 __smc_release+0x634/0x880 net/smc/af_smc.c:294 smc_release+0x1fc/0x620 net/smc/af_smc.c:361 __sock_release+0xb3/0x260 net/socket.c:735 sock_close+0x1c/0x30 net/socket.c:1529 __fput+0x3fb/0xb50 fs/file_table.c:512 fput_close_sync+0x118/0x250 fs/file_table.c:618 filp_close_sync+0x75/0xa0 fs/open.c:1573 __range_close+0x4a6/0x8b0 fs/file.c:919 __do_sys_close_range fs/file.c:1003 [inline] __se_sys_close_range fs/file.c:954 [inline] __ia32_sys_close_range+0x1f8/0x430 fs/file.c:954 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x14b/0x8c0 arch/x86/entry/syscall_32.c:282 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:307 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 *** locks held by syz.0.2076/12953: 3, last CPU#3: #0: ffff88806c403bc0 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #0: ffff88806c403bc0 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x86/0x260 net/socket.c:734 #1: ffff88806c1c0260 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x3a5/0x620 net/smc/af_smc.c:353 #2: ffffffff8ffeb260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #2: ffffffff8ffeb260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8ffeb260 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4515 [inline] #2: ffffffff8ffeb260 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xfd/0xd20 kernel/workqueue.c:4573 stack backtrace: CPU: 3 UID: 0 PID: 12953 Comm: syz.0.2076 Tainted: G L Y syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP, [Y]=FORCED_BIND Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_circular_bug.cold+0x178/0x1be kernel/locking/lockdep.c:2087 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2219 check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3209 check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x1528/0x1f40 kernel/locking/lockdep.c:5288 lock_acquire kernel/locking/lockdep.c:5942 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899 touch_work_lockdep_map kernel/workqueue.c:4287 [inline] start_flush_work kernel/workqueue.c:4541 [inline] __flush_work+0x54d/0xd20 kernel/workqueue.c:4573 __cancel_work_sync kernel/workqueue.c:4729 [inline] cancel_work_sync+0xcc/0xf0 kernel/workqueue.c:4766 smc_clcsock_release+0x5f/0xe0 net/smc/smc_close.c:29 __smc_release+0x5c2/0x880 net/smc/af_smc.c:318 smc_close_non_accepted+0xda/0x200 net/smc/af_smc.c:1870 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline] smc_close_active+0x4ff/0x11a0 net/smc/smc_close.c:226 __smc_release+0x634/0x880 net/smc/af_smc.c:294 smc_release+0x1fc/0x620 net/smc/af_smc.c:361 __sock_release+0xb3/0x260 net/socket.c:735 sock_close+0x1c/0x30 net/socket.c:1529 __fput+0x3fb/0xb50 fs/file_table.c:512 fput_close_sync+0x118/0x250 fs/file_table.c:618 filp_close_sync+0x75/0xa0 fs/open.c:1573 __range_close+0x4a6/0x8b0 fs/file.c:919 __do_sys_close_range fs/file.c:1003 [inline] __se_sys_close_range fs/file.c:954 [inline] __ia32_sys_close_range+0x1f8/0x430 fs/file.c:954 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x14b/0x8c0 arch/x86/entry/syscall_32.c:282 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:307 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7fb2fbc Code: d2 74 05 c1 e8 0c 89 02 8b 5d fc 31 c0 c9 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 2e 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 58 b8 RSP: 002b:00000000f546650c EFLAGS: 00000292 ORIG_RAX: 00000000000001b4 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000ffffffff RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: d2 74 05 c1 shlb %cl,-0x3f(%rbp,%rax,1) 4: e8 0c 89 02 8b call 0x8b028915 9: 5d pop %rbp a: fc cld b: 31 c0 xor %eax,%eax d: c9 leave e: c3 ret f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 0f 1f 00 nopl (%rax) 21: 51 push %rcx 22: 52 push %rdx 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: 2e 8d b4 26 00 00 00 cs lea 0x0(%rsi,%riz,1),%esi 36: 00 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 3e: 58 pop %rax 3f: b8 .byte 0xb8