====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.5.1723/11097 is trying to acquire lock: ffff88803fa3fae8 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: touch_work_lockdep_map kernel/workqueue.c:4044 [inline] ffff88803fa3fae8 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4298 [inline] ffff88803fa3fae8 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x4ca/0xcb0 kernel/workqueue.c:4330 but task is already holding lock: ffff88803fd28260 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x3a5/0x620 net/smc/af_smc.c:351 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+0x41/0xf0 net/core/sock.c:3783 smc_listen_out+0x1f5/0x4b0 net/smc/af_smc.c:1933 smc_listen_out_connected net/smc/af_smc.c:1953 [inline] smc_listen_decline net/smc/af_smc.c:1988 [inline] smc_listen_work+0x767/0x50e0 net/smc/af_smc.c:2585 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314 process_scheduled_works kernel/workqueue.c:3397 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x14b8/0x2630 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b1/0x370 kernel/locking/lockdep.c:5825 touch_work_lockdep_map kernel/workqueue.c:4044 [inline] start_flush_work kernel/workqueue.c:4298 [inline] __flush_work+0x4de/0xcb0 kernel/workqueue.c:4330 __cancel_work_sync kernel/workqueue.c:4486 [inline] cancel_work_sync+0xd1/0xf0 kernel/workqueue.c:4523 smc_clcsock_release+0x5f/0xe0 net/smc/smc_close.c:29 __smc_release+0x5c2/0x880 net/smc/af_smc.c:316 smc_close_non_accepted+0xda/0x200 net/smc/af_smc.c:1864 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline] smc_close_active+0x4ff/0x1070 net/smc/smc_close.c:225 __smc_release+0x634/0x880 net/smc/af_smc.c:292 smc_release+0x1fc/0x620 net/smc/af_smc.c:359 __sock_release+0xb3/0x260 net/socket.c:722 sock_close+0x1c/0x30 net/socket.c:1514 __fput+0x3ff/0xb50 fs/file_table.c:510 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0x107/0x4f0 kernel/entry/common.c:98 __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:318 [inline] do_syscall_64+0x706/0xf80 arch/x86/entry/syscall_64.c:100 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 *** 3 locks held by syz.5.1723/11097: #0: ffff88803b9f5c40 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline] #0: ffff88803b9f5c40 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x86/0x260 net/socket.c:721 #1: ffff88803fd28260 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x3a5/0x620 net/smc/af_smc.c:351 #2: ffffffff8e7e5620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #2: ffffffff8e7e5620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8e7e5620 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4272 [inline] #2: ffffffff8e7e5620 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xfd/0xcb0 kernel/workqueue.c:4330 stack backtrace: CPU: 2 UID: 0 PID: 11097 Comm: syz.5.1723 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP 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+0x178/0x1c7 kernel/locking/lockdep.c:2043 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x14b8/0x2630 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b1/0x370 kernel/locking/lockdep.c:5825 touch_work_lockdep_map kernel/workqueue.c:4044 [inline] start_flush_work kernel/workqueue.c:4298 [inline] __flush_work+0x4de/0xcb0 kernel/workqueue.c:4330 __cancel_work_sync kernel/workqueue.c:4486 [inline] cancel_work_sync+0xd1/0xf0 kernel/workqueue.c:4523 smc_clcsock_release+0x5f/0xe0 net/smc/smc_close.c:29 __smc_release+0x5c2/0x880 net/smc/af_smc.c:316 smc_close_non_accepted+0xda/0x200 net/smc/af_smc.c:1864 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline] smc_close_active+0x4ff/0x1070 net/smc/smc_close.c:225 __smc_release+0x634/0x880 net/smc/af_smc.c:292 smc_release+0x1fc/0x620 net/smc/af_smc.c:359 __sock_release+0xb3/0x260 net/socket.c:722 sock_close+0x1c/0x30 net/socket.c:1514 __fput+0x3ff/0xb50 fs/file_table.c:510 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0x107/0x4f0 kernel/entry/common.c:98 __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:318 [inline] do_syscall_64+0x706/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f68fcd9ce59 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:00007ffd18fad838 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007ffd18fad920 RCX: 00007f68fcd9ce59 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 000000000003171c R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b32020000 R11: 0000000000000246 R12: 00007ffd18fad960 R13: 00007f68fd015fac R14: 0000000000031786 R15: 00007f68fd015fa0 batadv_slave_1: left promiscuous mode