syzbot


INFO: task hung in jfs_link

Status: auto-obsoleted due to no activity on 2025/05/30 00:39
Subsystems: jfs
[Documentation on labels]
First crash: 176d, last: 176d

Sample crash report:
INFO: task syz.4.264:8682 blocked for more than 143 seconds.
      Not tainted 6.14.0-rc4-syzkaller-00199-g76544811c850 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.264       state:D stack:26016 pid:8682  tgid:8679  ppid:7529   task_flags:0x400040 flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0x18bc/0x4c40 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6857
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914
 __mutex_lock_common kernel/locking/mutex.c:662 [inline]
 __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730
 jfs_link+0x249/0x650 fs/jfs/namei.c:810
 vfs_link+0x4f0/0x6e0 fs/namei.c:4795
 do_linkat+0x555/0x6f0 fs/namei.c:4865
 __do_sys_link fs/namei.c:4899 [inline]
 __se_sys_link fs/namei.c:4897 [inline]
 __x64_sys_link+0x82/0x90 fs/namei.c:4897
 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: 0033:0x7f8c8458d169
RSP: 002b:00007f8c8544d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000056
RAX: ffffffffffffffda RBX: 00007f8c847a6160 RCX: 00007f8c8458d169
RDX: 0000000000000000 RSI: 0000400000000300 RDI: 0000400000000200
RBP: 00007f8c8460e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f8c847a6160 R15: 00007ffd43b69a18
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746
4 locks held by kworker/u8:5/1891:
 #0: ffff888141ada148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff888141ada148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319
 #1: ffffc900045c7c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc900045c7c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319
 #2: ffff88806b4000e0 (&type->s_umount_key#109){++++}-{4:4}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562
 #3: ffff88807bdd2fe0 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x24a/0x590 fs/jfs/inode.c:102
2 locks held by getty/5577:
 #0: ffff888035faa0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002ff62f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211
2 locks held by kworker/u8:11/8024:
4 locks held by syz.4.264/8681:
4 locks held by syz.4.264/8682:
 #0: ffff88806b400420 (sb_writers#31){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:547
 #1: ffff888052ac8578 (&type->i_mutex_dir_key#20/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:912 [inline]
 #1: ffff888052ac8578 (&type->i_mutex_dir_key#20/1){+.+.}-{4:4}, at: filename_create+0x260/0x540 fs/namei.c:4082
 #2: ffff888052ac97e8 (&sb->s_type->i_mutex_key#38){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline]
 #2: ffff888052ac97e8 (&sb->s_type->i_mutex_key#38){+.+.}-{4:4}, at: vfs_link+0x3b2/0x6e0 fs/namei.c:4786
 #3: ffff888052ac81c8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_link+0x249/0x650 fs/jfs/namei.c:810
2 locks held by syz.8.279/8984:
 #0: ffff88806b4000e0 (&type->s_umount_key#109){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88806b4000e0 (&type->s_umount_key#109){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120
 #1: ffff8881433b87d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
 #1: ffff8881433b87d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819
2 locks held by syz.7.371/10246:
 #0: ffff88806b4000e0 (&type->s_umount_key#109){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88806b4000e0 (&type->s_umount_key#109){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120
 #1: ffff8881433b87d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
 #1: ffff8881433b87d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819
1 lock held by syz.8.520/11638:
3 locks held by syz.6.519/11639:
 #0: ffff888041b80920 (&c->sb_lock){+.+.}-{4:4}, at: bch2_fs_alloc fs/bcachefs/super.c:833 [inline]
 #0: ffff888041b80920 (&c->sb_lock){+.+.}-{4:4}, at: bch2_fs_open+0x1604/0x31e0 fs/bcachefs/super.c:2064
 #1: ffff888041b849b0 (&c->mark_lock){++++}-{0:0}, at: bch2_sb_replicas_to_cpu_replicas+0x1e0/0x2e0 fs/bcachefs/replicas.c:600
 #2: ffffffff8eb3e478 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline]
 #2: ffffffff8eb3e478 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x820 kernel/rcu/tree_exp.h:996
9 locks held by cmp/11653:
1 lock held by udevadm/11654:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc4-syzkaller-00199-g76544811c850 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 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:236 [inline]
 watchdog+0x1058/0x10a0 kernel/hung_task.c:399
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 11654 Comm: udevadm Not tainted 6.14.0-rc4-syzkaller-00199-g76544811c850 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:check_preemption_disabled+0x60/0x120 lib/smp_processor_id.c:19
Code: 00 48 3b 44 24 08 0f 85 ce 00 00 00 89 d8 48 83 c4 10 5b 41 5c 41 5e 41 5f c3 cc cc cc cc 48 c7 04 24 00 00 00 00 9c 8f 04 24 <f7> 04 24 00 02 00 00 74 c5 49 89 f6 49 89 ff 65 4c 8b 24 25 00 d5
RSP: 0018:ffffc90004057788 EFLAGS: 00000046
RAX: 0000000080000000 RBX: 0000000000000000 RCX: ffffffff819cb224
RDX: 0000000000000000 RSI: ffffffff8c2ab240 RDI: ffffffff8c801b40
RBP: ffffc90004057910 R08: ffffffff903bc377 R09: 1ffffffff207786e
R10: dffffc0000000000 R11: fffffbfff207786f R12: 1ffff9200080af00
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000246
FS:  00007f84cecc3c80(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffcd0c2000 CR3: 000000006b358000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lockdep_recursion_inc kernel/locking/lockdep.c:464 [inline]
 lock_acquire+0x1b0/0x550 kernel/locking/lockdep.c:5850
 rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 rcu_read_lock include/linux/rcupdate.h:849 [inline]
 is_bpf_text_address+0x46/0x2a0 kernel/bpf/core.c:772
 kernel_text_address+0xa7/0xe0 kernel/extable.c:125
 __kernel_text_address+0xd/0x40 kernel/extable.c:79
 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369
 arch_stack_walk+0xfd/0x150 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4609 [inline]
 kmem_cache_free+0x195/0x410 mm/slub.c:4711
 do_readlinkat+0x2be/0x3a0 fs/stat.c:584
 __do_sys_readlink fs/stat.c:601 [inline]
 __se_sys_readlink fs/stat.c:598 [inline]
 __x64_sys_readlink+0x7f/0x90 fs/stat.c:598
 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: 0033:0x7f84ce917d47
Code: 73 01 c3 48 8b 0d e1 90 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 59 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d b1 90 0d 00 f7 d8 64 89 01 48
RSP: 002b:00007fffcd0c5578 EFLAGS: 00000202 ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 000055cf2a9be770 RCX: 00007f84ce917d47
RDX: 0000000000000400 RSI: 00007fffcd0c5988 RDI: 00007fffcd0c5588
RBP: 00007fffcd0c5dc8 R08: 000055cf0dfa67b7 R09: 0000000000000000
R10: 0000000000000010 R11: 0000000000000202 R12: 0000000000000200
R13: 00007fffcd0c5988 R14: 00007fffcd0c5588 R15: 000055cf2a9acda0
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/01 00:29 upstream 76544811c850 67cf5345 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in jfs_link
* Struck through repros no longer work on HEAD.