syzbot

INFO: task syz-executor374:7984 blocked for more than 140 seconds.
      Not tainted 4.14.304-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor374 D28448  7984   7982 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2811 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3387
 schedule+0x8d/0x1b0 kernel/sched/core.c:3431
 fuse_wait_on_page_writeback fs/fuse/file.c:385 [inline]
 fuse_wait_on_page_writeback.isra.0+0xdc/0x120 fs/fuse/file.c:381
 fuse_launder_page fs/fuse/file.c:2042 [inline]
 fuse_launder_page+0xa2/0xd0 fs/fuse/file.c:2035
 do_launder_page mm/truncate.c:609 [inline]
 invalidate_inode_pages2_range+0x547/0xc00 mm/truncate.c:685
 fuse_finish_open+0x262/0x500 fs/fuse/file.c:181
 fuse_open_common+0x234/0x290 fs/fuse/file.c:224
 do_dentry_open+0x44b/0xec0 fs/open.c:777
 vfs_open+0x105/0x220 fs/open.c:888
 do_last fs/namei.c:3428 [inline]
 path_openat+0x628/0x2970 fs/namei.c:3571
 do_filp_open+0x179/0x3c0 fs/namei.c:3605
 do_sys_open+0x296/0x410 fs/open.c:1081
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3
RIP: 0033:0x7f6be7bfa4c9
RSP: 002b:00007f6be7bab2f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f6be7c8b4c0 RCX: 00007f6be7bfa4c9
RDX: 0000000000000000 RSI: 0000000000003f00 RDI: 0000000020000080
RBP: 00007f6be7c58164 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e
R13: 00007f6be7c54158 R14: 00007f6be7c56160 R15: 00007f6be7c8b4c8

Showing all locks held in the system:
1 lock held by khungtaskd/1534:
 #0:  (tasklist_lock){.+.+}, at: [<ffffffff8702d8de>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548
1 lock held by systemd-journal/4625:
 #0:  (&rq->lock){-.-.}, at: [<ffffffff813dbfa4>] idle_balance kernel/sched/fair.c:8471 [inline]
 #0:  (&rq->lock){-.-.}, at: [<ffffffff813dbfa4>] pick_next_task_fair+0x554/0x1450 kernel/sched/fair.c:6379
2 locks held by syz-executor374/7984:
 #0:  (sb_writers#10){.+.+}, at: [<ffffffff818e1d0a>] sb_start_write include/linux/fs.h:1551 [inline]
 #0:  (sb_writers#10){.+.+}, at: [<ffffffff818e1d0a>] mnt_want_write+0x3a/0xb0 fs/namespace.c:386
 #1:  (&sb->s_type->i_mutex_key#17){+.+.}, at: [<ffffffff822f7bd4>] inode_lock include/linux/fs.h:719 [inline]
 #1:  (&sb->s_type->i_mutex_key#17){+.+.}, at: [<ffffffff822f7bd4>] fuse_open_common+0x1a4/0x290 fs/fuse/file.c:217

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 1534 Comm: khungtaskd Not tainted 4.14.304-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline]
 watchdog+0x5b9/0xb40 kernel/hung_task.c:274
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:406
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4625 Comm: systemd-journal Not tainted 4.14.304-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
task: ffff8880a11f2180 task.stack: ffff8880a11f8000
RIP: 0010:lock_unpin_lock+0x0/0x410 kernel/locking/lockdep.c:4082
RSP: 0018:ffff8880a11ffaa8 EFLAGS: 00000046
RAX: ffff8880a11ffc10 RBX: 000000010000da89 RCX: 1ffffffff0f13638
RDX: dffffc0000000000 RSI: 000000000000e3f4 RDI: ffff8880ba434418
RBP: ffff8880ba434400 R08: ffff8880ba434510 R09: ffff8880a11f2358
R10: ffff8880a11f2388 R11: 0000000000000000 R12: 0000000000000000
R13: 000000c7dabaee74 R14: ffff8880a11f8000 R15: dffffc0000000000
FS:  00007ffb4071c8c0(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffb3daeb010 CR3: 00000000a129f000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 rq_unpin_lock kernel/sched/sched.h:943 [inline]
 idle_balance kernel/sched/fair.c:8417 [inline]
 pick_next_task_fair+0x1d5/0x1450 kernel/sched/fair.c:6379
 pick_next_task kernel/sched/core.c:3235 [inline]
 __schedule+0x502/0x1de0 kernel/sched/core.c:3360
 schedule+0x8d/0x1b0 kernel/sched/core.c:3431
 schedule_hrtimeout_range_clock+0x2d0/0x320 kernel/time/hrtimer.c:1707
 ep_poll+0x85e/0xa50 fs/eventpoll.c:1827
 SYSC_epoll_wait fs/eventpoll.c:2195 [inline]
 SyS_epoll_wait+0x150/0x1a0 fs/eventpoll.c:2160
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3
RIP: 0033:0x7ffb3f9e52e3
RSP: 002b:00007ffcf0635618 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8
RAX: ffffffffffffffda RBX: 0000563c734211e0 RCX: 00007ffb3f9e52e3
RDX: 0000000000000013 RSI: 00007ffcf0635620 RDI: 0000000000000008
RBP: 00007ffcf0635810 R08: 00007ffcf0658000 R09: 000000dd6a6b62b6
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffcf0635620
R13: 0000000000000001 R14: ffffffffffffffff R15: 0005f34145ae10e9
Code: 7c ff ff ff e8 c2 c0 3d 00 e9 56 ff ff ff e8 a8 c1 3d 00 e9 d0 fe ff ff e8 7e c2 3d 00 e9 3e fe ff ff 66 0f 1f 84 00 00 00 00 00 <41> 57 41 56 41 55 41 54 49 89 fc 55 53 48 83 ec 58 48 c7 44 24