INFO: task syz-executor143:8105 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor143 D27392 8105 8103 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 fuse_wait_on_page_writeback fs/fuse/file.c:383 [inline] fuse_wait_on_page_writeback.isra.0+0x11b/0x170 fs/fuse/file.c:379 fuse_launder_page fs/fuse/file.c:2033 [inline] fuse_launder_page+0xb6/0xe0 fs/fuse/file.c:2026 do_launder_page mm/truncate.c:655 [inline] invalidate_inode_pages2_range+0x795/0x1110 mm/truncate.c:725 fuse_finish_open+0x2e2/0x590 fs/fuse/file.c:182 fuse_open_common+0x254/0x2c0 fs/fuse/file.c:222 do_dentry_open+0x4aa/0x1160 fs/open.c:796 do_last fs/namei.c:3421 [inline] path_openat+0x793/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_sys_open+0x3b3/0x520 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f7c78fe44c9 Code: Bad RIP value. RSP: 002b:00007f7c78f952f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007f7c790754c0 RCX: 00007f7c78fe44c9 RDX: 00007f7c78fe44c9 RSI: 0000000000000000 RDI: 00000000200001c0 RBP: 00007f7c79042164 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e R13: 00007f7c7903e158 R14: 00007f7c79040160 R15: 00007f7c790754c8 Showing all locks held in the system: 1 lock held by khungtaskd/1570: #0: 00000000da4e9c45 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by in:imklog/7890: #0: 000000006b9fd1d0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 2 locks held by syz-executor143/8105: #0: 000000003823985d (sb_writers#11){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline] #0: 000000003823985d (sb_writers#11){.+.+}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:360 #1: 000000001e73a638 (&sb->s_type->i_mutex_key#17){+.+.}, at: inode_lock include/linux/fs.h:748 [inline] #1: 000000001e73a638 (&sb->s_type->i_mutex_key#17){+.+.}, at: fuse_open_common+0x1bc/0x2c0 fs/fuse/file.c:215 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10 Comm: rcu_preempt Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0x1ef/0x3ff0 kernel/locking/lockdep.c:3295 Code: 48 81 c4 98 01 00 00 44 89 f8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 80 3c 02 00 <0f> 85 b3 2a 00 00 49 81 3e 20 f2 66 8c 0f 84 65 ff ff ff 83 fe 01 RSP: 0018:ffff8880b5a67858 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 1ffffffff1a77214 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000000001 R13: ffff8880b5a4e280 R14: ffffffff8d3b90a0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa67f5c2000 CR3: 00000000a1b38000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:152 debug_object_assert_init lib/debugobjects.c:676 [inline] debug_object_assert_init+0xfd/0x2e0 lib/debugobjects.c:665 debug_timer_assert_init kernel/time/timer.c:733 [inline] debug_assert_init kernel/time/timer.c:785 [inline] try_to_del_timer_sync+0x6d/0x110 kernel/time/timer.c:1235 del_timer_sync+0x1a4/0x270 kernel/time/timer.c:1305 schedule_timeout+0x4d7/0xfe0 kernel/time/timer.c:1819 rcu_gp_kthread+0xdad/0x21c0 kernel/rcu/tree.c:2202 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 ---------------- Code disassembly (best guess): 0: 48 81 c4 98 01 00 00 add $0x198,%rsp 7: 44 89 f8 mov %r15d,%eax a: 5b pop %rbx b: 5d pop %rbp c: 41 5c pop %r12 e: 41 5d pop %r13 10: 41 5e pop %r14 12: 41 5f pop %r15 14: c3 retq 15: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1c: fc ff df 1f: 4c 89 f2 mov %r14,%rdx 22: 48 c1 ea 03 shr $0x3,%rdx 26: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) * 2a: 0f 85 b3 2a 00 00 jne 0x2ae3 <-- trapping instruction 30: 49 81 3e 20 f2 66 8c cmpq $0xffffffff8c66f220,(%r14) 37: 0f 84 65 ff ff ff je 0xffffffa2 3d: 83 fe 01 cmp $0x1,%esi