INFO: task syz-executor286:8100 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-executor286 D28008 8100 8098 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: 0033:0x7fafb99824c9 Code: Bad RIP value. RSP: 002b:00007fafb99332f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007fafb9a134c0 RCX: 00007fafb99824c9 RDX: 00007fafb99824c9 RSI: 0000000000000000 RDI: 00000000200001c0 RBP: 00007fafb99e0164 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e R13: 00007fafb99dc158 R14: 00007fafb99de160 R15: 00007fafb9a134c8 Showing all locks held in the system: 1 lock held by khungtaskd/1571: #0: 00000000e7588019 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 2 locks held by syz-executor286/8100: #0: 00000000fc1ca9f9 (sb_writers#11){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline] #0: 00000000fc1ca9f9 (sb_writers#11){.+.+}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:360 #1: 000000000aa970f1 (&sb->s_type->i_mutex_key#17){+.+.}, at: inode_lock include/linux/fs.h:748 [inline] #1: 000000000aa970f1 (&sb->s_type->i_mutex_key#17){+.+.}, at: fuse_open_common+0x1bc/0x2c0 fs/fuse/file.c:215 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1571 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4690 Comm: systemd-journal Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:do_syscall_64+0x37e/0x620 arch/x86/entry/common.c:297 Code: fa 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e d4 01 00 00 83 63 08 f9 0f 1f 44 00 00 e8 d9 0b 62 00 0f 00 2d 02 e4 5f 07 <48> 83 c4 08 5b 5d 41 5c 41 5d e9 c3 0b 62 00 e8 be 0b 62 00 48 b8 RSP: 0018:ffff8880a0cf7f28 EFLAGS: 000000d3 RAX: ffff8880a0cea500 RBX: ffff8880a0cea500 RCX: ffffffff81007956 RDX: 0000000000000000 RSI: ffffffff81007997 RDI: ffff8880a0cea508 RBP: ffff8880a0cf7f58 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000100 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fba9c2298c0(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fba995fa000 CR3: 00000000a116f000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fba9b7b8210 Code: 73 01 c3 48 8b 0d 98 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d b9 c1 20 00 00 75 10 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 4e fc ff ff 48 89 04 24 RSP: 002b:00007ffecd468328 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: 0000000000000029 RBX: 00007ffecd46ada0 RCX: 00007fba9b7b8210 RDX: 0000000000002000 RSI: 00007ffecd468ba0 RDI: 0000000000000009 RBP: 0000000000000000 R08: 0000000000000008 R09: 000000b8c573d8c3 R10: 0001c83bf385a74b R11: 0000000000000246 R12: 00007ffecd468ba0 R13: 00007ffecd46acf8 R14: 000055d5ec73f958 R15: 0005db2f32d45356 ---------------- Code disassembly (best guess): 0: fa cli 1: 48 c1 ea 03 shr $0x3,%rdx 5: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax 9: 84 c0 test %al,%al b: 74 08 je 0x15 d: 3c 03 cmp $0x3,%al f: 0f 8e d4 01 00 00 jle 0x1e9 15: 83 63 08 f9 andl $0xfffffff9,0x8(%rbx) 19: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 1e: e8 d9 0b 62 00 callq 0x620bfc 23: 0f 00 2d 02 e4 5f 07 verw 0x75fe402(%rip) # 0x75fe42c * 2a: 48 83 c4 08 add $0x8,%rsp <-- trapping instruction 2e: 5b pop %rbx 2f: 5d pop %rbp 30: 41 5c pop %r12 32: 41 5d pop %r13 34: e9 c3 0b 62 00 jmpq 0x620bfc 39: e8 be 0b 62 00 callq 0x620bfc 3e: 48 rex.W 3f: b8 .byte 0xb8