syzbot


INFO: task hung in fuse_reverse_inval_entry

Status: upstream: reported C repro on 2021/09/05 19:48
Reported-by: syzbot+0821d8611ba946d5e4ab@syzkaller.appspotmail.com
First crash: 934d, last: 833d
Fix bisection: failed (error log, bisect log)
  
Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in fuse_reverse_inval_entry (2) fuse 3 1168d 1186d 0/26 auto-closed as invalid on 2021/04/15 03:59
linux-4.14 INFO: task hung in fuse_reverse_inval_entry C 1 402d 825d 0/1 upstream: reported C repro on 2021/12/23 18:36
upstream INFO: task hung in fuse_reverse_inval_entry fuse C done 23 2062d 2075d 13/26 fixed on 2019/11/11 16:48
upstream INFO: task hung in fuse_reverse_inval_entry (4) fuse 1 298d 298d 0/26 auto-obsoleted due to no activity on 2023/09/01 17:45
android-49 INFO: task hung in fuse_reverse_inval_entry C 3 2065d 1810d 0/3 public: reported C repro on 2019/04/14 08:51
upstream INFO: task hung in fuse_reverse_inval_entry (5) fuse 1 204d 204d 0/26 auto-obsoleted due to no activity on 2023/12/04 21:33
upstream INFO: task hung in fuse_reverse_inval_entry (3) fuse 1 474d 474d 0/26 auto-obsoleted due to no activity on 2023/04/10 13:00
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2021/11/04 20:30 12m bisect fix linux-4.19.y error job log (0)
2021/10/05 19:52 37m bisect fix linux-4.19.y job log (0) log

Sample crash report:
INFO: task syz-executor938:8082 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-executor938 D27952  8082   8080 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
 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline]
 rwsem_down_write_failed+0x3aa/0x760 kernel/locking/rwsem-xadd.c:618
 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:117
 __down_write arch/x86/include/asm/rwsem.h:142 [inline]
 down_write+0x4f/0x90 kernel/locking/rwsem.c:72
 inode_lock include/linux/fs.h:748 [inline]
 fuse_reverse_inval_entry+0xaa/0x660 fs/fuse/dir.c:987
 fuse_notify_inval_entry fs/fuse/dev.c:1535 [inline]
 fuse_notify fs/fuse/dev.c:1810 [inline]
 fuse_dev_do_write+0x251c/0x2bc0 fs/fuse/dev.c:1894
 fuse_dev_write+0x153/0x1e0 fs/fuse/dev.c:1978
 call_write_iter include/linux/fs.h:1821 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x51b/0x770 fs/read_write.c:487
 vfs_write+0x1f3/0x540 fs/read_write.c:549
 ksys_write+0x12b/0x2a0 fs/read_write.c:599
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fa76fb18b79
Code: Bad RIP value.
RSP: 002b:00007fa76fac22f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fa76fb9a4a0 RCX: 00007fa76fb18b79
RDX: 0000000000000029 RSI: 00000000200043c0 RDI: 0000000000000003
RBP: 00007fa76fb672d4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e
R13: 64695f70756f7267 R14: 2f30656c69662f2e R15: 00007fa76fb9a4a8
INFO: task syz-executor938:8085 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-executor938 D28488  8085   8080 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
 request_wait_answer+0x3dc/0x750 fs/fuse/dev.c:485
 __fuse_request_send+0x123/0x1c0 fs/fuse/dev.c:505
 fuse_simple_request+0x2e6/0x820 fs/fuse/dev.c:576
 fuse_lookup_name+0x24c/0x5c0 fs/fuse/dir.c:330
 fuse_lookup+0xdf/0x410 fs/fuse/dir.c:368
 __lookup_hash+0x117/0x180 fs/namei.c:1547
 filename_create+0x186/0x490 fs/namei.c:3639
 user_path_create fs/namei.c:3696 [inline]
 do_mkdirat+0xa0/0x2d0 fs/namei.c:3834
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fa76fb18b79
Code: Bad RIP value.
RSP: 002b:00007fa76faa12f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fa76fb9a4b0 RCX: 00007fa76fb18b79
RDX: 0000000000000000 RSI: 0000000020004380 RDI: 00000000ffffff9c
RBP: 00007fa76fb672d4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e
R13: 64695f70756f7267 R14: 2f30656c69662f2e R15: 00007fa76fb9a4b8

Showing all locks held in the system:
1 lock held by khungtaskd/1571:
 #0: 0000000021e1c10e (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441
1 lock held by in:imklog/7804:
 #0: 0000000074d9429a (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767
2 locks held by syz-executor938/8082:
 #0: 00000000ee9434ce (&fc->killsb){.+.+}, at: fuse_notify_inval_entry fs/fuse/dev.c:1532 [inline]
 #0: 00000000ee9434ce (&fc->killsb){.+.+}, at: fuse_notify fs/fuse/dev.c:1810 [inline]
 #0: 00000000ee9434ce (&fc->killsb){.+.+}, at: fuse_dev_do_write+0x24c7/0x2bc0 fs/fuse/dev.c:1894
 #1: 000000005e29af3a (&type->i_mutex_dir_key#8){+.+.}, at: inode_lock include/linux/fs.h:748 [inline]
 #1: 000000005e29af3a (&type->i_mutex_dir_key#8){+.+.}, at: fuse_reverse_inval_entry+0xaa/0x660 fs/fuse/dir.c:987
3 locks held by syz-executor938/8085:
 #0: 0000000099df943e (sb_writers#12){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline]
 #0: 0000000099df943e (sb_writers#12){.+.+}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:360
 #1: 000000005e29af3a (&type->i_mutex_dir_key#7/1){+.+.}, at: inode_lock_nested include/linux/fs.h:783 [inline]
 #1: 000000005e29af3a (&type->i_mutex_dir_key#7/1){+.+.}, at: filename_create+0x15a/0x490 fs/namei.c:3638
 #2: 000000004006c1e8 (&fi->mutex){+.+.}, at: fuse_lock_inode+0xaf/0xe0 fs/fuse/inode.c:365

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

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: 4694 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:__bpf_prog_run32+0x0/0xd0 kernel/bpf/core.c:1450
Code: 00 00 00 48 8b 8c 24 18 01 00 00 65 48 2b 0c 25 28 00 00 00 75 0c 48 81 c4 20 01 00 00 5b 5d 41 5c c3 e8 03 03 cb ff 0f 1f 00 <48> b8 00 00 00 00 00 fc ff df 41 54 49 89 fc 55 48 89 f5 53 48 81
RSP: 0018:ffff8880a0f57bb8 EFLAGS: 00000246
RAX: 1ffff9200035a406 RBX: ffff8880a10c76c0 RCX: ffffffff8162b98c
RDX: 0000000000000000 RSI: ffffc90001ad2038 RDI: ffff8880a0f57e70
RBP: ffffc90001ad2000 R08: 0000000000000000 R09: 000000007fff0000
R10: 0000000000000004 R11: 0000000000000000 R12: dffffc0000000000
R13: 000000007fff0000 R14: 000000007fff0000 R15: 000000007fff0000
FS:  00007fbf760d48c0(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbf734a9000 CR3: 00000000a140c000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 seccomp_run_filters+0x124/0x590 kernel/seccomp.c:211
 __seccomp_filter+0x93/0xca0 kernel/seccomp.c:667
 __secure_computing+0xfc/0x360 kernel/seccomp.c:796
 syscall_trace_enter+0x563/0xd60 arch/x86/entry/common.c:121
 do_syscall_64+0x486/0x620 arch/x86/entry/common.c:283
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fbf7536cf17
Code: ff ff ff 48 8b 4d a0 0f b7 51 fe 48 8b 4d a8 66 89 54 08 fe e9 1a ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 b8 27 00 00 00 0f 05 <c3> 0f 1f 84 00 00 00 00 00 b8 6e 00 00 00 0f 05 c3 0f 1f 84 00 00
RSP: 002b:00007ffdf62ab8d8 EFLAGS: 00000202 ORIG_RAX: 0000000000000027
RAX: ffffffffffffffda RBX: 0000562e06bf51e0 RCX: 00007fbf7536cf17
RDX: 00007ffdf62ab998 RSI: 0000000000000001 RDI: 0000562e06bf51e0
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000069 R11: 0000000000000202 R12: 00007ffdf62ab998
R13: 0000000000001256 R14: 00007ffdf62ae780 R15: 00007ffdf62abd90
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	00 48 8b             	add    %cl,-0x75(%rax)
   5:	8c 24 18             	mov    %fs,(%rax,%rbx,1)
   8:	01 00                	add    %eax,(%rax)
   a:	00 65 48             	add    %ah,0x48(%rbp)
   d:	2b 0c 25 28 00 00 00 	sub    0x28,%ecx
  14:	75 0c                	jne    0x22
  16:	48 81 c4 20 01 00 00 	add    $0x120,%rsp
  1d:	5b                   	pop    %rbx
  1e:	5d                   	pop    %rbp
  1f:	41 5c                	pop    %r12
  21:	c3                   	retq
  22:	e8 03 03 cb ff       	callq  0xffcb032a
  27:	0f 1f 00             	nopl   (%rax)
* 2a:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax <-- trapping instruction
  31:	fc ff df
  34:	41 54                	push   %r12
  36:	49 89 fc             	mov    %rdi,%r12
  39:	55                   	push   %rbp
  3a:	48 89 f5             	mov    %rsi,%rbp
  3d:	53                   	push   %rbx
  3e:	48                   	rex.W
  3f:	81                   	.byte 0x81

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/12/15 16:43 linux-4.19.y 3f8a27f9e27b f752fb53 .config console log report syz C ci2-linux-4-19 INFO: task hung in fuse_reverse_inval_entry
2021/09/05 19:47 linux-4.19.y b172b44fcb17 d236a457 .config console log report syz C ci2-linux-4-19 INFO: task hung in fuse_reverse_inval_entry
* Struck through repros no longer work on HEAD.