syzbot


INFO: task hung in find_inode_fast

Status: upstream: reported on 2024/11/20 14:47
Reported-by: syzbot+ba69aea6f458f1024dae@syzkaller.appspotmail.com
First crash: 2d22h, last: 2d22h
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in find_inode_fast (3) ext4 7 103d 200d 0/28 auto-obsoleted due to no activity on 2024/11/10 11:05
upstream INFO: task hung in find_inode_fast (2) ext4 C unreliable done 10 345d 498d 25/28 fixed on 2024/01/30 15:47
linux-5.15 INFO: task hung in find_inode_fast 3 562d 580d 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 536d 685d 22/28 fixed on 2023/06/08 14:41
linux-5.15 INFO: task hung in find_inode_fast (2) 1 22d 22d 0/3 upstream: reported on 2024/11/01 11:14

Sample crash report:
INFO: task syz.7.422:6400 blocked for more than 143 seconds.
      Not tainted 6.1.118-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.422       state:D stack:24552 pid:6400  ppid:5302   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 __wait_on_freeing_inode fs/inode.c:2282 [inline]
 find_inode_fast+0x315/0x450 fs/inode.c:991
 iget_locked+0xc7/0x830 fs/inode.c:1356
 __ext4_iget+0x25d/0x3ee0 fs/ext4/inode.c:4831
 ext4_xattr_inode_cache_find fs/ext4/xattr.c:1499 [inline]
 ext4_xattr_inode_lookup_create+0x4e8/0x1ef0 fs/ext4/xattr.c:1538
 ext4_xattr_block_set+0x2a1/0x3920 fs/ext4/xattr.c:1867
 ext4_xattr_set_handle+0xdac/0x1560 fs/ext4/xattr.c:2404
 ext4_xattr_set+0x26e/0x3d0 fs/ext4/xattr.c:2506
 __vfs_setxattr+0x3e7/0x420 fs/xattr.c:182
 __vfs_setxattr_noperm+0x12a/0x5e0 fs/xattr.c:216
 vfs_setxattr+0x21d/0x420 fs/xattr.c:309
 do_setxattr fs/xattr.c:594 [inline]
 setxattr+0x250/0x2b0 fs/xattr.c:617
 path_setxattr+0x1bc/0x2a0 fs/xattr.c:636
 __do_sys_setxattr fs/xattr.c:652 [inline]
 __se_sys_setxattr fs/xattr.c:648 [inline]
 __x64_sys_setxattr+0xb7/0xd0 fs/xattr.c:648
 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: 0033:0x7fbd2857e819
RSP: 002b:00007fbd2929b038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc
RAX: ffffffffffffffda RBX: 00007fbd28735fa0 RCX: 00007fbd2857e819
RDX: 0000000020001400 RSI: 00000000200001c0 RDI: 0000000020000380
RBP: 00007fbd285f175e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000835 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fbd28735fa0 R15: 00007fff7a5699d8
 </TASK>
INFO: task syz.7.422:6409 blocked for more than 143 seconds.
      Not tainted 6.1.118-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.422       state:D stack:23520 pid:6409  ppid:5302   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 mb_cache_entry_wait_unused+0x162/0x240 fs/mbcache.c:148
 ext4_evict_ea_inode+0x146/0x2e0 fs/ext4/xattr.c:444
 ext4_evict_inode+0x19d/0x1150 fs/ext4/inode.c:181
 evict+0x529/0x930 fs/inode.c:701
 ext4_xattr_ibody_set+0x58c/0x720 fs/ext4/xattr.c:2233
 ext4_xattr_set_handle+0xc72/0x1560 fs/ext4/xattr.c:2392
 ext4_xattr_set+0x26e/0x3d0 fs/ext4/xattr.c:2506
 __vfs_setxattr+0x3e7/0x420 fs/xattr.c:182
 __vfs_setxattr_noperm+0x12a/0x5e0 fs/xattr.c:216
 vfs_setxattr+0x21d/0x420 fs/xattr.c:309
 do_setxattr fs/xattr.c:594 [inline]
 setxattr+0x250/0x2b0 fs/xattr.c:617
 path_setxattr+0x1bc/0x2a0 fs/xattr.c:636
 __do_sys_setxattr fs/xattr.c:652 [inline]
 __se_sys_setxattr fs/xattr.c:648 [inline]
 __x64_sys_setxattr+0xb7/0xd0 fs/xattr.c:648
 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: 0033:0x7fbd2857e819
RSP: 002b:00007fbd283ff038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc
RAX: ffffffffffffffda RBX: 00007fbd28736080 RCX: 00007fbd2857e819
RDX: 0000000020001400 RSI: 00000000200001c0 RDI: 00000000200003c0
RBP: 00007fbd285f175e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000835 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fbd28736080 R15: 00007fff7a5699d8
 </TASK>
INFO: task syz.7.422:6412 blocked for more than 144 seconds.
      Not tainted 6.1.118-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.422       state:D stack:28200 pid:6412  ppid:5302   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 rwsem_down_write_slowpath+0xea1/0x14b0 kernel/locking/rwsem.c:1189
 inode_lock include/linux/fs.h:758 [inline]
 vfs_setxattr+0x1dd/0x420 fs/xattr.c:308
 do_setxattr fs/xattr.c:594 [inline]
 setxattr+0x250/0x2b0 fs/xattr.c:617
 path_setxattr+0x1bc/0x2a0 fs/xattr.c:636
 __do_sys_setxattr fs/xattr.c:652 [inline]
 __se_sys_setxattr fs/xattr.c:648 [inline]
 __x64_sys_setxattr+0xb7/0xd0 fs/xattr.c:648
 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: 0033:0x7fbd2857e819
RSP: 002b:00007fbd283de038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc
RAX: ffffffffffffffda RBX: 00007fbd28736160 RCX: 00007fbd2857e819
RDX: 0000000020001400 RSI: 00000000200001c0 RDI: 0000000020000200
RBP: 00007fbd285f175e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000835 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fbd28736160 R15: 00007fff7a5699d8
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d32b110 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d32b910 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
 #0: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510
2 locks held by kworker/1:1/41:
 #0: ffff888017c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90000b27d20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
4 locks held by kworker/u4:3/51:
 #0: ffff888017e16938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90000bc7d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8e4ef2d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf1/0xb60 net/core/net_namespace.c:566
 #3: ffffffff8e4fb668 (rtnl_mutex){+.+.}-{3:3}, at: ipmr_net_exit_batch+0x1c/0x90 net/ipv4/ipmr.c:3114
1 lock held by dhcpcd/3915:
 #0: ffffffff8e4fb668 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x12e/0x6c0 net/netlink/af_netlink.c:2302
2 locks held by getty/4003:
 #0: ffff88814df97098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc900032462f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198
3 locks held by syz.7.422/6400:
 #0: ffff8880585dc460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393
 #1: ffff888059ffca38 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff888059ffca38 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: vfs_setxattr+0x1dd/0x420 fs/xattr.c:308
 #2: ffff888059ffc700 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
 #2: ffff888059ffc700 (&ei->xattr_sem){++++}-{3:3}, at: ext4_xattr_set_handle+0x270/0x1560 fs/ext4/xattr.c:2319
3 locks held by syz.7.422/6409:
 #0: ffff8880585dc460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393
 #1: ffff88804fc40400 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff88804fc40400 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: vfs_setxattr+0x1dd/0x420 fs/xattr.c:308
 #2: ffff88804fc400c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
 #2: ffff88804fc400c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_xattr_set_handle+0x270/0x1560 fs/ext4/xattr.c:2319
2 locks held by syz.7.422/6412:
 #0: ffff8880585dc460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393
 #1: ffff88804fc40400 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff88804fc40400 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: vfs_setxattr+0x1dd/0x420 fs/xattr.c:308
4 locks held by kworker/u4:9/6438:
 #0: ffff888017c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90003a57d20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8e4fb668 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263
 #3: ffffffff8d330538 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
 #3: ffffffff8d330538 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4f0/0x930 kernel/rcu/tree_exp.h:962
2 locks held by syz-executor/6688:
 #0: ffff88805fad60e0 (&type->s_umount_key#58){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
 #1: ffffffff8d330538 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
 #1: ffffffff8d330538 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962
1 lock held by syz-executor/9754:
 #0: ffffffff8e4fb668 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e4fb668 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6147
2 locks held by syz.5.1118/9803:
 #0: ffffffff8e4ef2d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x378/0x5d0 net/core/net_namespace.c:477
 #1: ffffffff8e4fb668 (rtnl_mutex){+.+.}-{3:3}, at: tc_action_net_exit include/net/act_api.h:171 [inline]
 #1: ffffffff8e4fb668 (rtnl_mutex){+.+.}-{3:3}, at: gate_exit_net+0x2c/0x100 net/sched/act_gate.c:654
2 locks held by syz.6.1127/9856:
 #0: ffffffff8e4ef2d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x378/0x5d0 net/core/net_namespace.c:477
 #1: ffffffff8e4fb668 (rtnl_mutex){+.+.}-{3:3}, at: fib_net_exit_batch+0x1c/0x90 net/ipv4/fib_frontend.c:1638

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 6.1.118-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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+0x1ae/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:295
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4297 Comm: kworker/u4:5 Not tainted 6.1.118-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: bat_events batadv_nc_worker
RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline]
RIP: 0010:lock_release+0xcf/0xa20 kernel/locking/lockdep.c:5673
Code: 0d 0f 86 c2 05 00 00 89 db 48 89 d8 48 c1 e8 06 48 8d 3c c5 e8 0a 9a 8e be 08 00 00 00 e8 a9 58 77 00 48 0f a3 1d a9 52 2f 0d <73> 0d e8 5a bf 08 00 84 c0 0f 84 c5 05 00 00 48 c7 c0 a4 3f 9a 8e
RSP: 0018:ffffc900043bfa00 EFLAGS: 00000257
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff816ab837
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e9a0ae8
RBP: ffffc900043bfb38 R08: dffffc0000000000 R09: fffffbfff1d3415e
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000877f4c
R13: ffffffff8a7886ae R14: ffffffff8a7886ae R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562034374131 CR3: 000000000d08e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:165 [inline]
 _raw_spin_unlock_bh+0x17/0x30 kernel/locking/spinlock.c:210
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 batadv_nc_purge_paths+0x30e/0x3b0 net/batman-adv/network-coding.c:471
 batadv_nc_worker+0x324/0x610 net/batman-adv/network-coding.c:720
 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:295
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/20 14:46 linux-6.1.y b67dc5c9ade9 4fca1650 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in find_inode_fast
* Struck through repros no longer work on HEAD.