INFO: task syz.0.391:7575 blocked for more than 143 seconds. Not tainted 6.11.0-rc7-syzkaller-00021-g7c6a3a65ace7 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.391 state:D stack:21680 pid:7575 tgid:7575 ppid:6643 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 eventpoll_release_file+0xcb/0x1c0 fs/eventpoll.c:1106 eventpoll_release include/linux/eventpoll.h:53 [inline] __fput+0x6e0/0x8a0 fs/file_table.c:413 task_work_run+0x251/0x310 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: 0033:0x7f6c8bd7def9 RSP: 002b:00007ffe5db1da18 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f6c8bf37a80 RCX: 00007f6c8bd7def9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f6c8bf37a80 R08: 0000000000000006 R09: 00007ffe5db1dd0f R10: 00000000003ffcec R11: 0000000000000246 R12: 0000000000045536 R13: 00007ffe5db1db20 R14: 0000000000000032 R15: ffffffffffffffff Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6626 2 locks held by kworker/u8:8/2996: 2 locks held by getty/4981: #0: ffff888034ff20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ac/0x1e00 drivers/tty/n_tty.c:2211 1 lock held by syz.0.391/7575: #0: ffff888030879c68 (&ep->mtx){+.+.}-{3:3}, at: eventpoll_release_file+0xcb/0x1c0 fs/eventpoll.c:1106 2 locks held by syz.0.391/7576: 1 lock held by syz-executor/8238: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc7-syzkaller-00021-g7c6a3a65ace7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 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+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/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: 7576 Comm: syz.0.391 Not tainted 6.11.0-rc7-syzkaller-00021-g7c6a3a65ace7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:lockdep_hardirqs_off+0x53/0x110 kernel/locking/lockdep.c:4450 Code: 65 8b 05 98 3a 4a 74 a9 00 00 f0 00 74 66 83 3d 42 1d 7a 0e 00 75 15 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 <75> 7b 65 8b 05 9c ea 48 74 85 c0 74 54 65 48 8b 1c 25 00 d7 03 00 RSP: 0018:ffffc9000341f9f0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000040 RCX: ffffffff8be0176a RDX: 0000000000000000 RSI: ffffffff8c0ad580 RDI: ffffffff8c608f40 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88802dfb3c00 R13: 0000000000000000 R14: ffffffff8bb99097 R15: 0000000000000003 FS: 00007f6c8b7ff6c0(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020008040 CR3: 0000000069626000 CR4: 0000000000350ef0 Call Trace: irqentry_enter+0x2c/0x60 exc_page_fault+0x57/0x8c0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:__put_user_nocheck_4+0x7/0x20 arch/x86/lib/putuser.S:97 Code: d9 0f 01 cb 89 01 31 c9 0f 01 ca e9 ae b7 39 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 01 cb <89> 01 31 c9 0f 01 ca e9 88 b7 39 00 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc9000341fb38 EFLAGS: 00050246 RAX: 0000000000000008 RBX: ffff88802acb05ac RCX: 0000000020008040 RDX: ffff88802dfb3c00 RSI: 0000000000000008 RDI: 0000000000000000 RBP: ffffc9000341fdb8 R08: ffffffff822326e6 R09: 1ffff1100673db7b R10: dffffc0000000000 R11: ffffed100673db7c R12: 0000000020008040 R13: 0000000000000000 R14: 0000000000000008 R15: 1ffff110055960b5 epoll_put_uevent include/linux/eventpoll.h:81 [inline] ep_send_events fs/eventpoll.c:1876 [inline] ep_poll fs/eventpoll.c:2005 [inline] do_epoll_wait+0xe3a/0x2040 fs/eventpoll.c:2464 do_epoll_pwait+0x56/0x1e0 fs/eventpoll.c:2498 __do_sys_epoll_pwait fs/eventpoll.c:2511 [inline] __se_sys_epoll_pwait fs/eventpoll.c:2505 [inline] __x64_sys_epoll_pwait+0x2b8/0x310 fs/eventpoll.c:2505 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: 0033:0x7f6c8bd7def9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6c8b7ff038 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 RAX: ffffffffffffffda RBX: 00007f6c8bf35f80 RCX: 00007f6c8bd7def9 RDX: 0000000000000001 RSI: 0000000020008040 RDI: 0000000000000008 RBP: 00007f6c8bdf0b76 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000401 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6c8bf35f80 R15: 00007ffe5db1d8b8