INFO: task syz-executor252:8116 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-executor252 D27920 8116 8114 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: 0033:0x7f8e590c64c9 Code: Bad RIP value. RSP: 002b:00007f8e590772f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007f8e591574c0 RCX: 00007f8e590c64c9 RDX: 00007f8e590c64c9 RSI: 0000000000000140 RDI: 00000000200001c0 RBP: 00007f8e59124164 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e R13: 00007f8e59120158 R14: 00007f8e59122160 R15: 00007f8e591574c8 Showing all locks held in the system: 1 lock held by khungtaskd/1571: #0: 00000000fb378684 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by in:imklog/7811: #0: 00000000d8291f7d (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 2 locks held by syz-executor252/8116: #0: 000000004bd28fe9 (sb_writers#11){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline] #0: 000000004bd28fe9 (sb_writers#11){.+.+}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:360 #1: 0000000046266e71 (&sb->s_type->i_mutex_key#17){+.+.}, at: inode_lock include/linux/fs.h:748 [inline] #1: 0000000046266e71 (&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: 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4686 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:filename_lookup+0x0/0x5a0 fs/namei.c:2339 Code: e6 e4 90 ff 48 8b 7c 24 18 e8 9c a4 f1 ff e9 89 fc ff ff e8 32 a1 f1 ff e9 fa fe ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 <55> 48 89 e5 41 57 49 89 cf 41 56 49 89 f6 41 55 49 bd 00 00 00 00 RSP: 0018:ffff8880a111fe68 EFLAGS: 00000246 RAX: ffff8880b05c0c80 RBX: 0000000000000000 RCX: ffff8880a111feb0 RDX: 0000000000000001 RSI: ffff8880b05c0c80 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000000001 R13: ffff8880ae689900 R14: ffff8880a111feb0 R15: 0000000000000000 FS: 00007f15ab5778c0(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f15a8947000 CR3: 00000000a1127000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: user_path_at include/linux/namei.h:57 [inline] do_faccessat+0x248/0x7a0 fs/open.c:397 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f15aa8329c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007fffd54fc138 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007fffd54ff050 RCX: 00007f15aa8329c7 RDX: 00007f15ab2a3a00 RSI: 0000000000000000 RDI: 0000561048c859a3 RBP: 00007fffd54fc170 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fffd54ff050 R15: 00007fffd54fc660 ---------------- Code disassembly (best guess), 4 bytes skipped: 0: 48 8b 7c 24 18 mov 0x18(%rsp),%rdi 5: e8 9c a4 f1 ff callq 0xfff1a4a6 a: e9 89 fc ff ff jmpq 0xfffffc98 f: e8 32 a1 f1 ff callq 0xfff1a146 14: e9 fa fe ff ff jmpq 0xffffff13 19: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 20: 00 00 00 00 24: 66 90 xchg %ax,%ax * 26: 55 push %rbp <-- trapping instruction 27: 48 89 e5 mov %rsp,%rbp 2a: 41 57 push %r15 2c: 49 89 cf mov %rcx,%r15 2f: 41 56 push %r14 31: 49 89 f6 mov %rsi,%r14 34: 41 55 push %r13 36: 49 rex.WB 37: bd 00 00 00 00 mov $0x0,%ebp