Hello, syzbot found the following issue on: HEAD commit: 076d56d74f17 Add linux-next specific files for 20240202 git tree: linux-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=104ea9b7e80000 kernel config: https://syzkaller.appspot.com/x/.config?x=428086ff1c010d9f dashboard link: https://syzkaller.appspot.com/bug?extid=4bbc13a207327f82b3b0 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14a4ef2fe80000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1255e7c4180000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/dece45d1a4b5/disk-076d56d7.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/4921e269b178/vmlinux-076d56d7.xz kernel image: https://storage.googleapis.com/syzbot-assets/2a9156da9091/bzImage-076d56d7.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+4bbc13a207327f82b3b0@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task syz-executor268:5081 blocked for more than 143 seconds. Not tainted 6.8.0-rc2-next-20240202-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor268 state:D stack:26296 pid:5081 tgid:5081 ppid:5070 flags:0x00004006 Call Trace: <TASK> context_switch kernel/sched/core.c:5400 [inline] __schedule+0x17df/0x4a40 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6804 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6819 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2159 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x355/0x620 kernel/sched/completion.c:148 __flush_workqueue+0x730/0x1630 kernel/workqueue.c:3617 ceph_mdsc_pre_umount+0x5b5/0x8b0 fs/ceph/mds_client.c:5475 ceph_kill_sb+0x9f/0x4b0 fs/ceph/super.c:1535 deactivate_locked_super+0xc4/0x130 fs/super.c:477 ceph_get_tree+0x9a9/0x17b0 fs/ceph/super.c:1361 vfs_get_tree+0x90/0x2a0 fs/super.c:1784 vfs_cmd_create+0xe4/0x230 fs/fsopen.c:230 __do_sys_fsconfig fs/fsopen.c:476 [inline] __se_sys_fsconfig+0x967/0xec0 fs/fsopen.c:349 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7f1723f3ba39 RSP: 002b:00007ffde9dc2ba8 EFLAGS: 00000246 ORIG_RAX: 00000000000001af RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1723f3ba39 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000003 RBP: 00000000000143e0 R08: 0000000000000000 R09: 0000000000000006 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffde9dc2bbc R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001 </TASK> Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 2 locks held by getty/4823: #0: ffff88802b08d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031432f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201 2 locks held by syz-executor268/5081: #0: ffff888022c74c70 (&fc->uapi_mutex){+.+.}-{3:3}, at: __do_sys_fsconfig fs/fsopen.c:474 [inline] #0: ffff888022c74c70 (&fc->uapi_mutex){+.+.}-{3:3}, at: __se_sys_fsconfig+0x8e6/0xec0 fs/fsopen.c:349 #1: ffff888022e380e0 (&type->s_umount_key#41/1){+.+.}-{3:3}, at: alloc_super+0x20e/0x8f0 fs/super.c:345 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.8.0-rc2-next-20240202-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: <TASK> __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+0xfb0/0xff0 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242 </TASK> Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 11 Comm: kworker/u4:1 Not tainted 6.8.0-rc2-next-20240202-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:__text_poke+0x34b/0xd30 Code: e8 3a 08 c2 00 4c 8b b4 24 40 01 00 00 fa bb 00 02 00 00 be 00 02 00 00 4c 21 f6 31 ff e8 6d 18 5f 00 4c 21 f3 48 89 5c 24 50 <4c> 89 7c 24 38 75 07 e8 79 13 5f 00 eb 0a e8 72 13 5f 00 e8 fd 42 RSP: 0018:ffffc90000107780 EFLAGS: 00000006 RAX: 0000000000000000 RBX: 0000000000000200 RCX: ffff888016eabc00 RDX: 0000000000000000 RSI: 0000000000000200 RDI: 0000000000000000 RBP: ffffc90000107950 R08: ffffffff8134bcf3 R09: fffff52000020ec0 R10: dffffc0000000000 R11: fffff52000020ec0 R12: ffffea000007ad00 R13: fffffffffffffeff R14: 0000000000000246 R15: ffffffff81eb4896 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a9d88ed600 CR3: 000000000df32000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <TASK> text_poke arch/x86/kernel/alternative.c:1985 [inline] text_poke_bp_batch+0x59c/0xb30 arch/x86/kernel/alternative.c:2318 text_poke_flush arch/x86/kernel/alternative.c:2487 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2494 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_disable_cpuslocked+0xce/0x1c0 kernel/jump_label.c:235 static_key_disable+0x1a/0x20 kernel/jump_label.c:243 toggle_allocation_gate+0x1b8/0x250 mm/kfence/core.c:831 process_one_work kernel/workqueue.c:3049 [inline] process_scheduled_works+0x913/0x14f0 kernel/workqueue.c:3125 worker_thread+0xa60/0x1000 kernel/workqueue.c:3206 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242 </TASK> INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.413 msecs --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
