syzbot


INFO: task hung in __sb_start_write (3)

Status: auto-obsoleted due to no activity on 2024/10/20 14:57
Subsystems: f2fs
[Documentation on labels]
First crash: 320d, last: 320d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in __sb_start_write ext4 1508 2522d 2592d 0/28 closed as invalid on 2018/07/13 10:38
upstream INFO: task hung in __sb_start_write (2) ext4 3 2462d 2461d 0/28 closed as invalid on 2018/09/17 14:02

Sample crash report:
INFO: task syz.1.419:9298 blocked for more than 143 seconds.
      Not tainted 6.10.0-syzkaller-11840-g933069701c1b #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.419       state:D stack:24672 pid:9298  tgid:9298  ppid:8847   flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 percpu_rwsem_wait+0x3c2/0x450 kernel/locking/percpu-rwsem.c:162
 __percpu_down_read+0xee/0x130 kernel/locking/percpu-rwsem.c:177
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 __sb_start_write+0x188/0x1c0 include/linux/fs.h:1675
 sb_start_pagefault include/linux/fs.h:1840 [inline]
 f2fs_vm_page_mkwrite+0x5e4/0x1440 fs/f2fs/file.c:103
 do_page_mkwrite+0x19b/0x480 mm/memory.c:3142
 wp_page_shared mm/memory.c:3545 [inline]
 do_wp_page+0x23d9/0x52f0 mm/memory.c:3695
 handle_pte_fault+0x1138/0x6eb0 mm/memory.c:5538
 __handle_mm_fault mm/memory.c:5665 [inline]
 handle_mm_fault+0xf0b/0x1800 mm/memory.c:5830
 do_user_addr_fault arch/x86/mm/fault.c:1338 [inline]
 handle_page_fault arch/x86/mm/fault.c:1481 [inline]
 exc_page_fault+0x459/0x8c0 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f72c073d95d
RSP: 002b:00007ffc17d53ff8 EFLAGS: 00010287
RAX: 00000000200002c0 RBX: 0000000000000004 RCX: ffffffffffffffd7
RDX: 0000000000000028 RSI: 00007f72c020ca2d RDI: 00000000200002c0
RBP: fffffffffffffffe R08: 00007f72c0600000 R09: 0000000000000050
R10: 0000000000000000 R11: 0000000000000000 R12: 00007f72c0906044
R13: 0000000000000032 R14: 00007f72c0907a60 R15: 00007ffc17d540e0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e337560 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #0: ffffffff8e337560 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e337560 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6620
4 locks held by kworker/u8:9/2455:
 #0: ffff888015edb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff888015edb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc90009747d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc90009747d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffffffff8f5e9950 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:594
 #3: ffffffff8f5f64c8 (rtnl_mutex){+.+.}-{3:3}, at: fib6_rules_net_exit_batch+0x20/0xc0 net/ipv6/fib6_rules.c:510
4 locks held by udevd/4545:
 #0: ffff888047c341c8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb7/0xd60 fs/seq_file.c:182
 #1: ffff88801f079088 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154
 #2: ffff88805ae0ec38 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x72/0x3b0 fs/kernfs/file.c:155
 #3: ffff88802322e0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline]
 #3: ffff88802322e0e8 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17d/0x340 drivers/base/core.c:2743
2 locks held by getty/4846:
 #0: ffff88802fac80a0 (&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+0x6b5/0x1e10 drivers/tty/n_tty.c:2211
3 locks held by kworker/0:3/5140:
 #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc90003ff7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc90003ff7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffff88806e3fb240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x2d1/0x4130 drivers/net/netdevsim/fib.c:1489
3 locks held by kworker/0:4/5141:
 #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffff8880b9428948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x441/0x770 kernel/sched/psi.c:989
 #2: ffff88807b4b8538 (&idev->mc_lock){+.+.}-{3:3}, at: mld_dad_work+0x3c/0x500 net/ipv6/mcast.c:2258
3 locks held by kworker/1:5/5142:
 #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc90004017d00 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc90004017d00 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffffffff8e33c800 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4486
3 locks held by kworker/0:6/5145:
 #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc90004057d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc90004057d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffff888071649240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x2d1/0x4130 drivers/net/netdevsim/fib.c:1489
2 locks held by syz.1.419/9298:
 #0: ffff8880625ab580 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:683 [inline]
 #0: ffff8880625ab580 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x2f9/0x6e0 mm/memory.c:5986
 #1: ffff88804c5cc518 (sb_pagefaults#5){++++}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1840 [inline]
 #1: ffff88804c5cc518 (sb_pagefaults#5){++++}-{0:0}, at: f2fs_vm_page_mkwrite+0x5e4/0x1440 fs/f2fs/file.c:103
3 locks held by kworker/u8:14/10048:
 #0: ffff888029f37148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff888029f37148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc90002e9fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc90002e9fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffffffff8f5f64c8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4194
1 lock held by syz-executor/11186:
 #0: ffffffff8f5f64c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8f5f64c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644
1 lock held by syz-executor/11226:
 #0: ffffffff8f5f64c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8f5f64c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644
7 locks held by syz-executor/11228:
 #0: ffff88802a504420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2876 [inline]
 #0: ffff88802a504420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x227/0xc90 fs/read_write.c:586
 #1: ffff888079c0c488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1eb/0x500 fs/kernfs/file.c:325
 #2: ffff88802321ff08 (kn->active#50){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20f/0x500 fs/kernfs/file.c:326
 #3: ffffffff8eef84a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: new_device_store+0x1b4/0x890 drivers/net/netdevsim/bus.c:166
 #4: ffff88806b6580e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline]
 #4: ffff88806b6580e8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8e/0x520 drivers/base/dd.c:1003
 #5: ffff88806b659250 (&devlink->lock_key#53){+.+.}-{3:3}, at: nsim_drv_probe+0xcb/0xb80 drivers/net/netdevsim/dev.c:1534
 #6: ffffffff8f5f64c8 (rtnl_mutex){+.+.}-{3:3}, at: register_nexthop_notifier+0x84/0x290 net/ipv4/nexthop.c:3871
2 locks held by syz-executor/11274:
 #0: ffffffff8f5f64c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8f5f64c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644
 #1: ffffffff8e33c938 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:328 [inline]
 #1: ffffffff8e33c938 (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 6.10.0-syzkaller-11840-g933069701c1b #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+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/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: 4527 Comm: syslogd Not tainted 6.10.0-syzkaller-11840-g933069701c1b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
RIP: 0010:__sanitizer_cov_trace_switch+0x90/0x120 kernel/kcov.c:340
Code: 85 d2 75 14 e9 9a 00 00 00 41 b8 05 00 00 00 4d 85 d2 0f 84 8b 00 00 00 4c 8b 4c 24 20 65 4c 8b 1c 25 00 d7 03 00 31 d2 eb 08 <48> ff c2 49 39 d2 74 71 4c 8b 74 d6 10 65 8b 05 64 4f 70 7e a9 00
RSP: 0018:ffffc9000d4bf340 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000002 RCX: ffff88807a34bc00
RDX: 0000000000000000 RSI: ffffffff8e1a3280 RDI: 0000000000000002
RBP: ffffffff90ae97d8 R08: 0000000000000003 R09: ffffffff81410e12
R10: 0000000000000002 R11: ffff88807a34bc00 R12: ffffffff90121788
R13: dffffc0000000000 R14: 0000000000000000 R15: ffffffff90ae97d4
FS:  00007f80e73fb380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564102424950 CR3: 000000002d5f2000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 unwind_next_frame+0x6c2/0x2a00 arch/x86/kernel/unwind_orc.c:505
 arch_stack_walk+0x151/0x1b0 arch/x86/kernel/stacktrace.c:25
 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:579
 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2252 [inline]
 slab_free mm/slub.c:4473 [inline]
 kfree+0x149/0x360 mm/slub.c:4594
 skb_kfree_head net/core/skbuff.c:1084 [inline]
 skb_free_head net/core/skbuff.c:1096 [inline]
 skb_release_data+0x676/0x880 net/core/skbuff.c:1123
 skb_release_all net/core/skbuff.c:1188 [inline]
 __kfree_skb net/core/skbuff.c:1202 [inline]
 consume_skb+0xb1/0x160 net/core/skbuff.c:1426
 __unix_dgram_recvmsg+0xcea/0x12f0 net/unix/af_unix.c:2527
 sock_recvmsg_nosec net/socket.c:1046 [inline]
 sock_recvmsg+0x22f/0x280 net/socket.c:1068
 sock_read_iter+0x2ca/0x3e0 net/socket.c:1138
 new_sync_read fs/read_write.c:395 [inline]
 vfs_read+0x9bd/0xbc0 fs/read_write.c:476
 ksys_read+0x1a0/0x2c0 fs/read_write.c:619
 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: 0033:0x7f80e754fb6a
Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffd46b22b88 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f80e754fb6a
RDX: 00000000000000ff RSI: 0000561cbe3b3950 RDI: 0000000000000000
RBP: 0000561cbe3b3910 R08: 0000000000000001 R09: 0000000000000000
R10: 00007f80e76ee3a3 R11: 0000000000000246 R12: 0000561cbe3b398d
R13: 0000561cbe3b3950 R14: 0000000000000000 R15: 00007f80e7732a80
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/07/22 14:54 upstream 933069701c1b df655b64 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in __sb_start_write
* Struck through repros no longer work on HEAD.