INFO: task syz-executor.4:6140 blocked for more than 143 seconds. Not tainted 6.8.0-rc5-syzkaller-00121-g1c892cdd8fe0 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:23568 pid:6140 tgid:6138 ppid:5114 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0x17d1/0x49f0 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6802 [inline] schedule+0x149/0x260 kernel/sched/core.c:6817 __lock_sock+0x1cc/0x330 net/core/sock.c:2948 lock_sock_nested+0x9e/0x100 net/core/sock.c:3528 lock_sock include/net/sock.h:1691 [inline] tcp_recvmsg+0x23b/0x920 net/ipv4/tcp.c:2576 inet_recvmsg+0x150/0x2d0 net/ipv4/af_inet.c:882 sock_recvmsg_nosec+0x126/0x1d0 net/socket.c:1046 ____sys_recvmsg+0x3c0/0x470 net/socket.c:2801 ___sys_recvmsg net/socket.c:2845 [inline] do_recvmmsg+0x474/0xae0 net/socket.c:2939 __sys_recvmmsg net/socket.c:3018 [inline] __do_sys_recvmmsg net/socket.c:3041 [inline] __se_sys_recvmmsg net/socket.c:3034 [inline] __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3034 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7f750987dda9 RSP: 002b:00007f750a62c0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f75099abf80 RCX: 00007f750987dda9 RDX: 000000003fffffff RSI: 0000000020001840 RDI: 0000000000000007 RBP: 00007f75098ca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f75099abf80 R15: 00007fff962629e8 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8e130c60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff8e130c60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff8e130c60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 2 locks held by kworker/u4:8/4319: #0: ffff888014c89538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #0: ffff888014c89538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #1: ffffc9000c997d20 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #1: ffffc9000c997d20 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 2 locks held by getty/4824: #0: ffff88803024a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031232f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b4/0x1e10 drivers/tty/n_tty.c:2201 3 locks held by kworker/1:20/5376: #0: ffff888014c88938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #0: ffff888014c88938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #1: ffffc90004cffd20 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #1: ffffc90004cffd20 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #2: ffffffff8e1365f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #2: ffffffff8e1365f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x46c/0x890 kernel/rcu/tree_exp.h:995 2 locks held by kworker/u4:2/5866: #0: ffff888014c89538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #0: ffff888014c89538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #1: ffffc90014fb7d20 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #1: ffffc90014fb7d20 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 2 locks held by kworker/u4:9/5880: 1 lock held by syz-executor.4/6140: #0: ffff88807e0925f0 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1691 [inline] #0: ffff88807e0925f0 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_recvmsg+0x23b/0x920 net/ipv4/tcp.c:2576 3 locks held by syz-executor.4/6146: 3 locks held by syz-executor.1/9497: 2 locks held by syz-executor.2/9511: #0: ffffffff9484ce98 (nfnl_subsys_ipset){+.+.}-{3:3}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline] #0: ffffffff9484ce98 (nfnl_subsys_ipset){+.+.}-{3:3}, at: nfnetlink_rcv_msg+0xa5c/0x1190 net/netfilter/nfnetlink.c:295 #1: ffffffff8e1364c0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x550 kernel/rcu/tree.c:4064 2 locks held by syz-executor.3/9514: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.8.0-rc5-syzkaller-00121-g1c892cdd8fe0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xfaf/0xff0 kernel/hung_task.c:379 kthread+0x2f1/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5109 Comm: syz-executor.2 Not tainted 6.8.0-rc5-syzkaller-00121-g1c892cdd8fe0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 RIP: 0010:__switch_to_asm+0x60/0x70 arch/x86/entry/entry_64.S:210 Code: 00 00 cc e8 01 00 00 00 cc 48 83 c4 10 49 ff cc 75 eb 0f ae e8 65 48 c7 04 25 10 bf 03 00 ff ff ff ff 41 5f 41 5e 41 5d 41 5c <5b> 5d e9 09 5e 31 00 66 0f 1f 84 00 00 00 00 00 66 2e 0f 1f 84 00 RSP: 0018:ffffc9000324f248 EFLAGS: 00000046 RAX: 1ffff110172a792a RBX: fc20c5e61a0ede00 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffff8880234d9dc0 RDI: ffff888028bb5940 RBP: ffffc90004437be0 R08: ffffffff8f8566ef R09: 1ffffffff1f0acdd R10: dffffc0000000000 R11: fffffbfff1f0acde R12: ffff8880234da2f0 R13: 0000000000000000 R14: dffffc0000000000 R15: dffffc0000000000 FS: 0000555557076480(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f31467ad988 CR3: 0000000081620000 CR4: 0000000000350ef0 Call Trace: