syzbot


INFO: task hung in gfs2_glock_nq

Status: upstream: reported C repro on 2024/04/13 10:45
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+7aebfd340e5ced0abdf8@syzkaller.appspotmail.com
First crash: 62d, last: 48d
Fix bisection: failed (error log, bisect log)
  
Bug presence (1)
Date Name Commit Repro Result
2024/04/14 upstream (ToT) 7efd0a74039f C [report] INFO: task hung in gfs2_glock_nq
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in gfs2_glock_nq gfs2 C 23 31d 58d 0/27 upstream: reported C repro on 2024/04/17 16:54
linux-6.1 INFO: task hung in gfs2_glock_nq origin:upstream C 7 13d 64d 0/3 upstream: reported C repro on 2024/04/11 08:56

Sample crash report:
INFO: task syz-executor411:4004 blocked for more than 143 seconds.
      Not tainted 5.15.155-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor411 state:D stack:    0 pid: 4004 ppid:  4002 flags:0x00000004
Call trace:
 __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6376
 schedule+0x11c/0x1c8 kernel/sched/core.c:6459
 bit_wait+0x1c/0xac kernel/sched/wait_bit.c:199
 __wait_on_bit kernel/sched/wait_bit.c:49 [inline]
 out_of_line_wait_on_bit+0x208/0x33c kernel/sched/wait_bit.c:64
 wait_on_bit include/linux/wait_bit.h:76 [inline]
 gfs2_glock_wait fs/gfs2/glock.c:1280 [inline]
 gfs2_glock_nq+0xb38/0x144c fs/gfs2/glock.c:1536
 gfs2_glock_nq_init fs/gfs2/glock.h:246 [inline]
 __gfs2_lookup+0x114/0x260 fs/gfs2/inode.c:882
 gfs2_lookup+0x2c/0x3c fs/gfs2/inode.c:907
 __lookup_slow+0x250/0x388 fs/namei.c:1663
 lookup_slow+0x60/0x84 fs/namei.c:1680
 walk_component+0x394/0x4cc fs/namei.c:1976
 lookup_last fs/namei.c:2431 [inline]
 path_lookupat+0x13c/0x3d0 fs/namei.c:2455
 filename_lookup+0x1c4/0x4c8 fs/namei.c:2484
 user_path_at_empty+0x5c/0x1a4 fs/namei.c:2883
 user_path_at include/linux/namei.h:57 [inline]
 ksys_umount fs/namespace.c:1779 [inline]
 __do_sys_umount fs/namespace.c:1787 [inline]
 __se_sys_umount fs/namespace.c:1785 [inline]
 __arm64_sys_umount+0xf8/0x17c fs/namespace.c:1785
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffff800014b114e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:311
2 locks held by getty/3724:
 #0: ffff0000d2ad2098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
 #1: ffff800018e262e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1204 drivers/tty/n_tty.c:2158
1 lock held by syz-executor411/4004:
 #0: ffff0000df4e2338 (&type->i_mutex_dir_key#6){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:799 [inline]
 #0: ffff0000df4e2338 (&type->i_mutex_dir_key#6){.+.+}-{3:3}, at: lookup_slow+0x50/0x84 fs/namei.c:1679

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


Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/13 23:26 linux-5.15.y fa3df276cd36 c8349e48 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 INFO: task hung in gfs2_glock_nq
2024/04/27 14:41 linux-5.15.y c52b9710c83d 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in gfs2_glock_nq
2024/04/18 13:46 linux-5.15.y c52b9710c83d af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in gfs2_glock_nq
2024/04/18 13:41 linux-5.15.y c52b9710c83d af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in gfs2_glock_nq
2024/04/13 10:44 linux-5.15.y cdfd0a7f0139 c8349e48 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in gfs2_glock_nq
* Struck through repros no longer work on HEAD.