BTRFS error (device loop4): superblock checksum mismatch BTRFS error (device loop4): open_ctree failed BTRFS error (device loop4): unsupported checksum algorithm 3786 BTRFS error (device loop4): superblock checksum mismatch BTRFS error (device loop4): open_ctree failed INFO: task syz-executor0:29557 blocked for more than 140 seconds. Not tainted 4.19.0-rc1+ #218 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D23416 29557 4646 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x87c/0x1df0 kernel/sched/core.c:3473 schedule+0xfb/0x450 kernel/sched/core.c:3517 __rwsem_down_write_failed_common+0x98b/0x1650 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0xaa/0x130 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:738 [inline] do_truncate+0x19f/0x2b0 fs/open.c:61 handle_truncate fs/namei.c:3008 [inline] do_last fs/namei.c:3424 [inline] path_openat+0x34e3/0x5340 fs/namei.c:3534 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x584/0x720 fs/open.c:1063 __do_sys_openat fs/open.c:1090 [inline] __se_sys_openat fs/open.c:1084 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1084 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457099 Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007feef4c44c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007feef4c456d4 RCX: 0000000000457099 RDX: 0000000000002761 RSI: 0000000020000180 RDI: ffffffffffffffff RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d3318 R14: 00000000004c819c R15: 0000000000000001 Showing all locks held in the system: 4 locks held by kworker/u4:2/54: 1 lock held by khungtaskd/792: #0: 00000000e4610af8 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4436 1 lock held by rsyslogd/4506: #0: 000000006488729c (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/4596: #0: 00000000f3eb3c7c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000285d4f33 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4597: #0: 0000000039562048 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000032ed59cc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4598: #0: 0000000057c14b9e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000001d252a8f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4599: #0: 0000000051d24e58 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000cc67edbc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4600: #0: 00000000b989019c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000003e994f5c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4601: #0: 00000000b531ae03 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000fb4e30de (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4602: #0: 0000000034ad0def (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e1deadc5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor0/4646: 4 locks held by syz-executor0/29548: 2 locks held by syz-executor0/29557: #0: 000000008a85fafc (sb_writers#13){.+.+}, at: sb_start_write include/linux/fs.h:1566 [inline] #0: 000000008a85fafc (sb_writers#13){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 0000000012b9b3cc (&sb->s_type->i_mutex_key#18){++++}, at: inode_lock include/linux/fs.h:738 [inline] #1: 0000000012b9b3cc (&sb->s_type->i_mutex_key#18){++++}, at: do_truncate+0x19f/0x2b0 fs/open.c:61 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 792 Comm: khungtaskd Not tainted 4.19.0-rc1+ #218 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+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.3+0x48/0x88 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0xb39/0x1040 kernel/hung_task.c:265 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 Sending NMI from CPU 0 to CPUs 1: INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.630 msecs NMI backtrace for cpu 1 CPU: 1 PID: 4646 Comm: syz-executor0 Not tainted 4.19.0-rc1+ #218 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:69 [inline] RIP: 0010:write_comp_data+0x22/0x70 kernel/kcov.c:122 Code: b4 c7 ca ff 90 90 90 90 55 65 4c 8b 04 25 40 ee 01 00 65 8b 05 af 2d 85 7e 48 89 e5 a9 00 01 1f 00 75 51 41 8b 80 88 12 00 00 <83> f8 03 75 45 49 8b 80 90 12 00 00 45 8b 80 8c 12 00 00 4c 8b 08 RSP: 0018:ffff880195e5e468 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000004 RCX: ffffffff819b0f21 RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000005 RBP: ffff880195e5e468 R08: ffff880195e50580 R09: fffff94000cd50f6 R10: fffff94000cd50f6 R11: ffffea00066a87b7 R12: ffffea00066a8780 R13: ffff880195e5e798 R14: 1ffff10032bcbcab R15: dffffc0000000000 FS: 00000000016c4940(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000177a000 CR3: 0000000195e02000 CR4: 00000000001406e0 Call Trace: __sanitizer_cov_trace_const_cmp4+0x16/0x20 kernel/kcov.c:188 atomic_fetch_add_unless include/linux/atomic.h:578 [inline] atomic_add_unless include/linux/atomic.h:597 [inline] page_ref_add_unless include/linux/page_ref.h:157 [inline] get_page_unless_zero include/linux/mm.h:531 [inline] page_cache_get_speculative include/linux/pagemap.h:186 [inline] find_get_entry+0x4a1/0xc90 mm/filemap.c:1448 pagecache_get_page+0x11e/0xe40 mm/filemap.c:1541 find_or_create_page include/linux/pagemap.h:322 [inline] grow_dev_page fs/buffer.c:948 [inline] grow_buffers fs/buffer.c:1017 [inline] __getblk_slow fs/buffer.c:1044 [inline] __getblk_gfp+0x3bb/0xb10 fs/buffer.c:1321 __bread_gfp+0x2d/0x310 fs/buffer.c:1355 sb_bread include/linux/buffer_head.h:307 [inline] fat__get_entry+0x59c/0xa30 fs/fat/dir.c:101 fat_get_entry fs/fat/dir.c:129 [inline] fat_search_long+0x33b/0x15d0 fs/fat/dir.c:477 vfat_find+0x16d/0x1a0 fs/fat/namei_vfat.c:697 vfat_lookup+0x107/0x640 fs/fat/namei_vfat.c:711 __lookup_slow+0x2b5/0x540 fs/namei.c:1671 lookup_slow+0x57/0x80 fs/namei.c:1688 walk_component+0x94a/0x2630 fs/namei.c:1810 link_path_walk.part.40+0xa6e/0x1540 fs/namei.c:2141 link_path_walk fs/namei.c:2072 [inline] path_openat+0x268/0x5340 fs/namei.c:3533 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x584/0x720 fs/open.c:1063 __do_sys_open fs/open.c:1081 [inline] __se_sys_open fs/open.c:1076 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1076 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4551a0 Code: 31 c0 e9 45 ff ff ff 0f 1f 00 80 3f 00 0f 84 f7 00 00 00 55 53 b9 02 00 00 00 be 00 08 09 00 89 c8 48 81 ec 98 00 00 00 0f 05 <48> 3d 00 f0 ff ff 48 89 c3 0f 87 e9 00 00 00 85 db 0f 88 2f 01 00 RSP: 002b:00007fff5bab6f70 EFLAGS: 00000202 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004551a0 RDX: 0000000000000000 RSI: 0000000000090800 RDI: 00000000004c1e40 RBP: 00000000000009df R08: 0000000000000001 R09: 00000000016c4940 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000010 R13: 00000000000a0be1 R14: 00000000000002b2 R15: badc0ffeebadface