INFO: task syz.4.413:6589 blocked for more than 143 seconds. Not tainted 6.11.0-syzkaller-11503-gc824deb1a897 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.413 state:D stack:23808 pid:6589 tgid:6589 ppid:5245 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6824 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752 pipe_fasync+0x4c/0x1f0 fs/pipe.c:752 __fput+0x71b/0x880 fs/file_table.c:428 task_work_run+0x24f/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7abdf7dff9 RSP: 002b:00007fff7bbcda58 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f7abe137a80 RCX: 00007f7abdf7dff9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f7abe137a80 R08: 0000000000000006 R09: 00007fff7bbcdd4f R10: 00000000003ffc7c R11: 0000000000000246 R12: 0000000000015006 R13: 00007fff7bbcdb60 R14: 0000000000000032 R15: ffffffffffffffff Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6701 2 locks held by getty/4983: #0: ffff88802e5410a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 3 locks held by syz-executor/5223: 2 locks held by syz.2.210/5961: #0: ffffffff8fd387b0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ec1ad88 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nl_listener_set_doit+0x12d/0x1a90 fs/nfsd/nfsctl.c:1964 1 lock held by syz.4.413/6589: #0: ffff888030978c68 (&pipe->mutex){+.+.}-{3:3}, at: pipe_fasync+0x4c/0x1f0 fs/pipe.c:752 1 lock held by syz.4.413/6597: #0: ffff888030978c68 (&pipe->mutex){+.+.}-{3:3}, at: splice_file_to_pipe+0x2e/0x500 fs/splice.c:1292 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-syzkaller-11503-gc824deb1a897 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 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:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5223 Comm: syz-executor Not tainted 6.11.0-syzkaller-11503-gc824deb1a897 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:should_fail_ex+0x0/0x4e0 lib/fault-inject.c:105 Code: fe ff ff 4c 89 ef e8 ff 3a 0c fd e9 a3 fe ff ff e8 65 d7 d2 06 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <66> 0f 1f 00 55 41 57 41 56 41 55 41 54 53 48 83 ec 18 89 14 24 49 RSP: 0018:ffffc90003ec7d50 EFLAGS: 00000246 RAX: ffffffff84f245d9 RBX: 00007ffe7928cc50 RCX: ffff88802c703c00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff8f0ac140 RBP: ffffc90003ec7e30 R08: ffffffff901cf8af R09: 1ffffffff2039f15 R10: dffffc0000000000 R11: fffffbfff2039f16 R12: 00007ffe7928cc50 R13: 1ffff920007d8fb0 R14: ffffc90003ec7da0 R15: 0000000000000018 FS: 0000555591070500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020001180 CR3: 0000000075314000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: _inline_copy_from_user include/linux/uaccess.h:162 [inline] _copy_from_user+0x2f/0xe0 lib/usercopy.c:18 copy_from_user include/linux/uaccess.h:203 [inline] restore_altstack+0x99/0x150 kernel/signal.c:4345 __do_sys_rt_sigreturn+0x17c/0x270 arch/x86/kernel/signal_64.c:263 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6ba5719959 Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25 RSP: 002b:00007ffe7928cc40 EFLAGS: 00000246 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 00007ffe7928d2f0 RCX: 00007f6ba5719959 RDX: 00007ffe7928cc40 RSI: 00007ffe7928cd70 RDI: 0000000000000011 RBP: 0000000000000000 R08: 000000002b878264 R09: 7fffffffffffffff R10: 00007f6ba65b60b8 R11: 0000000000000246 R12: 00007ffe7928d5f0 R13: 0000000000000004 R14: 00007ffe7928d1fc R15: 00007ffe7928d290