syzbot


INFO: task hung in find_inode_fast (3)

Status: auto-obsoleted due to no activity on 2024/11/10 11:05
Subsystems: ext4
[Documentation on labels]
First crash: 282d, last: 184d
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in find_inode_fast (4) ext4 syz error 5 31d 51d 0/28 upstream: reported syz repro on 2024/12/23 01:23
upstream INFO: task hung in find_inode_fast (2) ext4 C unreliable done 10 426d 580d 25/28 fixed on 2024/01/30 15:47
linux-5.15 INFO: task hung in find_inode_fast 3 643d 662d 0/3 auto-obsoleted due to no activity on 2023/08/23 09:07
upstream INFO: task hung in find_inode_fast ext4 C error 28 617d 766d 22/28 fixed on 2023/06/08 14:41
linux-6.1 INFO: task hung in find_inode_fast 1 84d 84d 0/3 upstream: reported on 2024/11/20 14:47
linux-5.15 INFO: task hung in find_inode_fast (2) 1 103d 103d 0/3 auto-obsoleted due to no activity on 2025/02/09 11:15

Sample crash report:
INFO: task syz.2.2000:13253 blocked for more than 143 seconds.
      Not tainted 6.11.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.2000      state:D stack:22840 pid:13253 tgid:13252 ppid:12779  flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x1800/0x4a60 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 __wait_on_freeing_inode+0x2bb/0x420 fs/inode.c:2320
 find_inode_fast+0x2a0/0x460 fs/inode.c:967
 iget_locked+0xab/0x820 fs/inode.c:1330
 __ext4_iget+0x267/0x4090 fs/ext4/inode.c:4761
 ext4_xattr_inode_cache_find fs/ext4/xattr.c:1548 [inline]
 ext4_xattr_inode_lookup_create+0x4f8/0x1f90 fs/ext4/xattr.c:1587
 ext4_xattr_ibody_set+0x214/0x730 fs/ext4/xattr.c:2269
 ext4_xattr_set_handle+0xba6/0x1580 fs/ext4/xattr.c:2446
 ext4_xattr_set+0x241/0x3d0 fs/ext4/xattr.c:2560
 __vfs_setxattr+0x46a/0x4a0 fs/xattr.c:200
 __vfs_setxattr_noperm+0x12e/0x660 fs/xattr.c:234
 vfs_setxattr+0x221/0x430 fs/xattr.c:321
 do_setxattr fs/xattr.c:629 [inline]
 path_setxattr+0x37e/0x4d0 fs/xattr.c:658
 __do_sys_setxattr fs/xattr.c:676 [inline]
 __se_sys_setxattr fs/xattr.c:672 [inline]
 __x64_sys_setxattr+0xbb/0xd0 fs/xattr.c:672
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f74e89779f9
RSP: 002b:00007f74e97aa038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc
RAX: ffffffffffffffda RBX: 00007f74e8b05f80 RCX: 00007f74e89779f9
RDX: 0000000020001400 RSI: 00000000200001c0 RDI: 0000000020000200
RBP: 00007f74e89e58ee R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000835 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f74e8b05f80 R15: 00007ffc60e7a6b8
 </TASK>
INFO: task syz.2.2000:13260 blocked for more than 144 seconds.
      Not tainted 6.11.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.2000      state:D stack:25312 pid:13260 tgid:13252 ppid:12779  flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x1800/0x4a60 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 mb_cache_entry_wait_unused+0x166/0x250 fs/mbcache.c:148
 ext4_evict_ea_inode+0x14a/0x2f0 fs/ext4/xattr.c:480
 ext4_evict_inode+0x194/0xf50 fs/ext4/inode.c:180
 evict+0x2aa/0x630 fs/inode.c:669
 ext4_xattr_set_entry+0x17f2/0x1f60 fs/ext4/xattr.c:1847
 ext4_xattr_ibody_set+0x268/0x730 fs/ext4/xattr.c:2274
 ext4_xattr_set_handle+0xba6/0x1580 fs/ext4/xattr.c:2446
 ext4_xattr_set+0x241/0x3d0 fs/ext4/xattr.c:2560
 __vfs_setxattr+0x46a/0x4a0 fs/xattr.c:200
 __vfs_setxattr_noperm+0x12e/0x660 fs/xattr.c:234
 vfs_setxattr+0x221/0x430 fs/xattr.c:321
 do_setxattr fs/xattr.c:629 [inline]
 path_setxattr+0x37e/0x4d0 fs/xattr.c:658
 __do_sys_setxattr fs/xattr.c:676 [inline]
 __se_sys_setxattr fs/xattr.c:672 [inline]
 __x64_sys_setxattr+0xbb/0xd0 fs/xattr.c:672
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f74e89779f9
RSP: 002b:00007f74e9768038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc
RAX: ffffffffffffffda RBX: 00007f74e8b06130 RCX: 00007f74e89779f9
RDX: 0000000020000100 RSI: 00000000200000c0 RDI: 0000000020000180
RBP: 00007f74e89e58ee R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000090f R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f74e8b06130 R15: 00007ffc60e7a6b8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e9382e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #0: ffffffff8e9382e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e9382e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6626
5 locks held by kworker/u8:2/35:
3 locks held by kworker/u8:4/62:
 #0: ffff88802a78a148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff88802a78a148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc900015d7d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc900015d7d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffffffff8fc82308 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4734
3 locks held by kworker/u8:7/2506:
 #0: ffff888015881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff888015881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc90009267d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc90009267d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffffffff8fc82308 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276
2 locks held by getty/4981:
 #0: ffff88802f7d00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ac/0x1e00 drivers/tty/n_tty.c:2211
6 locks held by kworker/u8:13/10076:
 #0: ffff8880166e5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff8880166e5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc90009107d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc90009107d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffffffff8fc75790 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:594
 #3: ffffffff8fc82308 (rtnl_mutex){+.+.}-{3:3}, at: wg_netns_pre_exit+0x1f/0x1e0 drivers/net/wireguard/device.c:414
 #4: ffff88805ca49428 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_netns_pre_exit+0xba/0x1e0 drivers/net/wireguard/device.c:419
 #5: ffffffff8e93d6b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:328 [inline]
 #5: ffffffff8e93d6b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:958
3 locks held by syz.2.2000/13253:
 #0: ffff888079104420 (sb_writers#4){++++}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515
 #1: ffff888024ee03f8 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:799 [inline]
 #1: ffff888024ee03f8 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: vfs_setxattr+0x1e1/0x430 fs/xattr.c:320
 #2: ffff888024ee00c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
 #2: ffff888024ee00c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_xattr_set_handle+0x277/0x1580 fs/ext4/xattr.c:2373
3 locks held by syz.2.2000/13260:
 #0: ffff888079104420 (sb_writers#4){++++}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515
 #1: ffff8880519771a0 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:799 [inline]
 #1: ffff8880519771a0 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: vfs_setxattr+0x1e1/0x430 fs/xattr.c:320
 #2: ffff888051976e70 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
 #2: ffff888051976e70 (&ei->xattr_sem){++++}-{3:3}, at: ext4_xattr_set_handle+0x277/0x1580 fs/ext4/xattr.c:2373
1 lock held by syz-executor/14500:
 #0: ffffffff8fc82308 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fc82308 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644
3 locks held by syz.5.2434/14710:
 #0: ffff888051a54a08 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:799 [inline]
 #0: ffff888051a54a08 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline]
 #0: ffff888051a54a08 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1421
 #1: ffff8880599b1258 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline]
 #1: ffff8880599b1258 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: pptp_release+0x52/0x300 drivers/net/ppp/pptp.c:508
 #2: ffffffff8e93d6b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:328 [inline]
 #2: ffffffff8e93d6b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:958

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:379
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 35 Comm: kworker/u8:2 Not tainted 6.11.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Workqueue: bat_events batadv_nc_worker
RIP: 0010:lock_release+0x658/0xa30 kernel/locking/lockdep.c:5784
Code: 3c 3b 00 74 08 4c 89 f7 e8 95 d5 8a 00 f6 84 24 91 00 00 00 02 75 77 41 f7 c5 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 4b c7 44 27 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc90000ab79a0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff92000156f46 RCX: ffffc90000ab7a03
RDX: 0000000000000002 RSI: ffffffff8c0ae6c0 RDI: ffffffff8c606400
RBP: ffffc90000ab7ad8 R08: ffffffff9017ce2f R09: 1ffffffff202f9c5
R10: dffffc0000000000 R11: fffffbfff202f9c6 R12: 1ffff92000156f40
R13: 0000000000000246 R14: ffffc90000ab7a30 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f00faed2ab8 CR3: 0000000022cc6000 CR4: 0000000000350ef0
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 rcu_lock_release include/linux/rcupdate.h:336 [inline]
 rcu_read_unlock include/linux/rcupdate.h:869 [inline]
 batadv_nc_process_nc_paths+0x2f0/0x3a0 net/batman-adv/network-coding.c:699
 batadv_nc_worker+0x42a/0x610 net/batman-adv/network-coding.c:728
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2e/0x1830 kernel/workqueue.c:3312
 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/12 10:54 upstream 7c626ce4bae1 6f4edef4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in find_inode_fast
2024/08/10 08:41 upstream afdab700f65e 6f4edef4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in find_inode_fast
2024/07/22 06:00 upstream 7846b618e0a4 b88348e9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in find_inode_fast
2024/07/22 05:46 upstream 7846b618e0a4 b88348e9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in find_inode_fast
2024/06/07 15:20 upstream 8a92980606e3 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in find_inode_fast
2024/05/12 20:19 upstream ba16c1cf11c9 9026e142 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in find_inode_fast
2024/05/06 16:40 upstream dd5a440a31fa c035c6de .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in find_inode_fast
* Struck through repros no longer work on HEAD.