syzbot


INFO: task hung in __gfs2_lookup

Status: upstream: reported C repro on 2024/04/20 00:06
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+622cd7bf75b161ab2e37@syzkaller.appspotmail.com
First crash: 31d, last: 23d
Bug presence (1)
Date Name Commit Repro Result
2024/04/20 upstream (ToT) 13a2e429f644 C [report] INFO: task hung in __gfs2_lookup
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in __gfs2_lookup gfs2 C error 110 6d20h 38d 0/26 upstream: reported C repro on 2024/04/12 09:00
linux-5.15 INFO: task hung in __gfs2_lookup origin:upstream C 6 28d 38d 0/3 upstream: reported C repro on 2024/04/13 05:13

Sample crash report:
INFO: task syz-executor300:3582 blocked for more than 143 seconds.
      Not tainted 6.1.87-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor300 state:D stack:23880 pid:3582  ppid:3580   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 bit_wait+0xe/0xc0 kernel/sched/wait_bit.c:199
 __wait_on_bit+0xa8/0x2e0 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0x1d0/0x250 kernel/sched/wait_bit.c:64
 wait_on_bit include/linux/wait_bit.h:76 [inline]
 gfs2_glock_wait+0xc3/0x2a0 fs/gfs2/glock.c:1346
 gfs2_glock_nq_init fs/gfs2/glock.h:264 [inline]
 __gfs2_lookup+0x117/0x270 fs/gfs2/inode.c:879
 __lookup_slow+0x27e/0x3d0 fs/namei.c:1690
 lookup_slow+0x53/0x70 fs/namei.c:1707
 walk_component+0x2d0/0x400 fs/namei.c:1998
 lookup_last fs/namei.c:2455 [inline]
 path_lookupat+0x16f/0x450 fs/namei.c:2479
 filename_lookup+0x251/0x600 fs/namei.c:2508
 user_path_at_empty+0x3e/0x60 fs/namei.c:2907
 user_path_at include/linux/namei.h:57 [inline]
 ksys_umount fs/namespace.c:1822 [inline]
 __do_sys_umount fs/namespace.c:1830 [inline]
 __se_sys_umount fs/namespace.c:1828 [inline]
 __x64_sys_umount+0xf0/0x170 fs/namespace.c:1828
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc347b02607
RSP: 002b:00007ffdd2211918 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc347b02607
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdd22119d0
RBP: 00007ffdd22119d0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000206 R12: 00007ffdd2212ac0
R13: 00005555555e5740 R14: 00005555555d4338 R15: 00007ffdd2214c0c
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d12ae50 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d12b650 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by khungtaskd/28:
 #0: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494
2 locks held by getty/3300:
 #0: ffff88814b9ec098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc9000312b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2188
1 lock held by syz-executor300/3582:
 #0: ffff888070409c30 (&type->i_mutex_dir_key#6){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline]
 #0: ffff888070409c30 (&type->i_mutex_dir_key#6){.+.+}-{3:3}, at: lookup_slow+0x45/0x70 fs/namei.c:1706

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

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.87-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1b0/0x3f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xf88/0xfd0 kernel/hung_task.c:377
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 46 Comm: kworker/u4:3 Not tainted 6.1.87-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:insn_get_opcode+0x2bf/0xa50
Code: 0f 85 34 07 00 00 41 89 2f 89 ee 83 e6 30 31 ff e8 e6 67 02 f7 89 e8 83 e0 30 48 8b 5c 24 50 0f 84 6e 04 00 00 4c 89 7c 24 40 <49> 8d 44 24 15 48 89 44 24 28 49 8d 44 24 03 48 89 44 24 68 4d 89
RSP: 0018:ffffc90000b776e0 EFLAGS: 00000202
RAX: 0000000000000010 RBX: ffffc90000b779e0 RCX: dffffc0000000000
RDX: ffff888018a88000 RSI: 0000000000000010 RDI: 0000000000000000
RBP: 0000000000000010 R08: ffffffff8a882ada R09: ffffc90000b77980
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffc90000b77980
R13: dffffc0000000000 R14: 000000000000000f R15: ffffc90000b779cc
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c36725b680 CR3: 000000000ce8e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 insn_get_modrm+0x22a/0x790 arch/x86/lib/insn.c:343
 insn_get_sib arch/x86/lib/insn.c:421 [inline]
 insn_get_displacement+0x13a/0x970 arch/x86/lib/insn.c:464
 insn_get_immediate+0x458/0x1390 arch/x86/lib/insn.c:632
 insn_get_length arch/x86/lib/insn.c:707 [inline]
 insn_decode+0x36c/0x500 arch/x86/lib/insn.c:747
 text_poke_loc_init+0xd2/0x680 arch/x86/kernel/alternative.c:1638
 arch_jump_label_transform_queue+0x71/0xd0 arch/x86/kernel/jump_label.c:138
 __jump_label_update+0x177/0x3a0 kernel/jump_label.c:447
 static_key_disable_cpuslocked+0xca/0x1b0 kernel/jump_label.c:207
 static_key_disable+0x16/0x20 kernel/jump_label.c:215
 toggle_allocation_gate+0x3e0/0x480 mm/kfence/core.c:818
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.364 msecs

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/20 03:12 linux-6.1.y 6741e066ec76 af24b050 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan INFO: task hung in __gfs2_lookup
2024/04/27 14:45 linux-6.1.y 6741e066ec76 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in __gfs2_lookup
2024/04/22 05:27 linux-6.1.y 6741e066ec76 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in __gfs2_lookup
2024/04/22 05:27 linux-6.1.y 6741e066ec76 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in __gfs2_lookup
2024/04/21 05:50 linux-6.1.y 6741e066ec76 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in __gfs2_lookup
2024/04/20 00:05 linux-6.1.y 6741e066ec76 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in __gfs2_lookup
* Struck through repros no longer work on HEAD.