syzbot


INFO: task hung in bch2_page_mkwrite

Status: auto-obsoleted due to no activity on 2024/08/06 23:06
Subsystems: bcachefs
[Documentation on labels]
First crash: 264d, last: 264d

Sample crash report:
INFO: task syz-executor.3:10190 blocked for more than 143 seconds.
      Not tainted 6.9.0-rc7-syzkaller-00023-g6d7ddd805123 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:24368 pid:10190 tgid:10190 ppid:9687   flags:0x00000006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0x1796/0x4a00 kernel/sched/core.c:6746
 __schedule_loop kernel/sched/core.c:6823 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6838
 __bch2_two_state_lock+0x171/0x200 fs/bcachefs/two_state_shared_lock.c:7
 bch2_two_state_lock fs/bcachefs/two_state_shared_lock.h:56 [inline]
 bch2_page_mkwrite+0x464/0xd90 fs/bcachefs/fs-io-pagecache.c:602
 do_page_mkwrite+0x19b/0x480 mm/memory.c:3091
 wp_page_shared mm/memory.c:3478 [inline]
 do_wp_page+0x2582/0x54a0 mm/memory.c:3628
 handle_pte_fault mm/memory.c:5316 [inline]
 __handle_mm_fault+0x264a/0x7250 mm/memory.c:5441
 handle_mm_fault+0x27f/0x770 mm/memory.c:5606
 do_user_addr_fault arch/x86/mm/fault.c:1331 [inline]
 handle_page_fault arch/x86/mm/fault.c:1474 [inline]
 exc_page_fault+0x446/0x8a0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f1acd2379ff
RSP: 002b:00007ffd6a089260 EFLAGS: 00010246
RAX: 0000000000000240 RBX: 0000000000000001 RCX: ffffffffffffffff
RDX: 575af63267696c85 RSI: 0000000020000000 RDI: 00005555852e2360
RBP: 00007ffd6a089318 R08: 00007f1acd200000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 000000000006b3b8
R13: 00007f1acd3ac12c R14: 00007ffd6a089340 R15: 0000000000000032
 </TASK>
INFO: task syz-executor.3:10225 blocked for more than 144 seconds.
      Not tainted 6.9.0-rc7-syzkaller-00023-g6d7ddd805123 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:15152 pid:10225 tgid:10190 ppid:9687   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0x1796/0x4a00 kernel/sched/core.c:6746
 __schedule_loop kernel/sched/core.c:6823 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6838
 __bch2_two_state_lock+0x171/0x200 fs/bcachefs/two_state_shared_lock.c:7
 bch2_two_state_lock fs/bcachefs/two_state_shared_lock.h:56 [inline]
 bch2_readahead+0xcf5/0x1870 fs/bcachefs/fs-io-buffered.c:277
 read_pages+0x17e/0x840 mm/readahead.c:160
 page_cache_ra_order+0x9ec/0xbd0 mm/readahead.c:528
 page_cache_sync_readahead include/linux/pagemap.h:1300 [inline]
 filemap_get_pages+0x49d/0x2090 mm/filemap.c:2505
 filemap_splice_read+0x654/0xeb0 mm/filemap.c:2870
 do_splice_read fs/splice.c:985 [inline]
 splice_direct_to_actor+0x4b7/0xc90 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0x28c/0x3e0 fs/splice.c:1233
 do_sendfile+0x56d/0xdc0 fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1348
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1acd27dd69
RSP: 002b:00007f1acdfea0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f1acd3ac050 RCX: 00007f1acd27dd69
RDX: 0000000000000000 RSI: 000000000000000d RDI: 000000000000000c
RBP: 00007f1acd2ca49e R08: 0000000000000000 R09: 0000000000000000
R10: 0001000200201005 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f1acd3ac050 R15: 00007ffd6a089178
 </TASK>
INFO: task syz-executor.3:10226 blocked for more than 144 seconds.
      Not tainted 6.9.0-rc7-syzkaller-00023-g6d7ddd805123 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:25744 pid:10226 tgid:10190 ppid:9687   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0x1796/0x4a00 kernel/sched/core.c:6746
 __schedule_loop kernel/sched/core.c:6823 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6838
 io_schedule+0x8d/0x110 kernel/sched/core.c:9044
 folio_wait_bit_common+0x882/0x12b0 mm/filemap.c:1283
 truncate_inode_pages_range+0xaaf/0xfc0 mm/truncate.c:412
 truncate_inode_pages mm/truncate.c:439 [inline]
 truncate_pagecache mm/truncate.c:732 [inline]
 truncate_setsize+0xcf/0xf0 mm/truncate.c:757
 bchfs_truncate+0x683/0xc80 fs/bcachefs/fs-io.c:450
 notify_change+0xb9d/0xe70 fs/attr.c:497
 do_truncate fs/open.c:65 [inline]
 do_ftruncate+0x46b/0x590 fs/open.c:181
 do_sys_ftruncate fs/open.c:199 [inline]
 __do_sys_ftruncate fs/open.c:207 [inline]
 __se_sys_ftruncate fs/open.c:205 [inline]
 __x64_sys_ftruncate+0x95/0xf0 fs/open.c:205
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1acd27dd69
RSP: 002b:00007f1acdfc90c8 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 00007f1acd3ac120 RCX: 00007f1acd27dd69
RDX: 0000000000000000 RSI: 0000000000010001 RDI: 000000000000000e
RBP: 00007f1acd2ca49e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f1acd3ac120 R15: 00007ffd6a089178
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
 #0: ffffffff8e33a138 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
 #0: ffffffff8e33a138 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x463/0x820 kernel/rcu/tree_exp.h:939
2 locks held by kworker/u8:0/10:
1 lock held by khungtaskd/29:
 #0: ffffffff8e334da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #0: ffffffff8e334da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #0: ffffffff8e334da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614
4 locks held by kworker/u8:3/50:
 #0: ffff888015ecb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3242 [inline]
 #0: ffff888015ecb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3348
 #1: ffffc90000ba7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3243 [inline]
 #1: ffffc90000ba7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3348
 #2: ffffffff8f587bd0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:591
 #3: ffffffff8f5942c8 (rtnl_mutex){+.+.}-{3:3}, at: cangw_pernet_exit_batch+0x20/0x90 net/can/gw.c:1257
1 lock held by dhcpcd/4741:
 #0: ffffffff8f5942c8 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x2ce/0x1bc0 net/ipv4/devinet.c:1096
2 locks held by getty/4835:
 #0: ffff88802a5a40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002f162f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201
3 locks held by kworker/1:4/5158:
 #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3242 [inline]
 #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3348
 #1: ffffc900042cfd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3243 [inline]
 #1: ffffc900042cfd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3348
 #2: ffffffff8f5942c8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276
2 locks held by syz-executor.3/10190:
 #0: ffff888023c84a90 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:677 [inline]
 #0: ffff888023c84a90 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x2f9/0x730 mm/memory.c:5762
 #1: ffff88802f3b0518 (sb_pagefaults#4){.+.+}-{0:0}, at: do_page_mkwrite+0x19b/0x480 mm/memory.c:3091
2 locks held by syz-executor.3/10225:
 #0: ffff88805609a090 (mapping.invalidate_lock#3){.+.+}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:850 [inline]
 #0: ffff88805609a090 (mapping.invalidate_lock#3){.+.+}-{3:3}, at: page_cache_ra_order+0x38f/0xbd0 mm/readahead.c:507
 #1: ffff88804c984250 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:116 [inline]
 #1: ffff88804c984250 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:215 [inline]
 #1: ffff88804c984250 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x8c8/0xc90 fs/bcachefs/btree_iter.c:3069
2 locks held by syz-executor.3/10226:
 #0: ffff88802f3b0420 (sb_writers#15){.+.+}-{0:0}, at: do_ftruncate+0x294/0x590 fs/open.c:178
 #1: ffff888056099ef0 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:795 [inline]
 #1: ffff888056099ef0 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: do_truncate fs/open.c:63 [inline]
 #1: ffff888056099ef0 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: do_ftruncate+0x457/0x590 fs/open.c:181
1 lock held by syz-executor.3/12434:
 #0: ffffffff8f5942c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8f5942c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x842/0x10d0 net/core/rtnetlink.c:6592
1 lock held by syz-executor.0/12475:
 #0: ffffffff8f5942c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8f5942c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x842/0x10d0 net/core/rtnetlink.c:6592
3 locks held by syz-executor.1/12612:

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

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.9.0-rc7-syzkaller-00023-g6d7ddd805123 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 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:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xfde/0x1020 kernel/hung_task.c:380
 kthread+0x2f0/0x390 kernel/kthread.c:388
 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 PID: 4509 Comm: syslogd Not tainted 6.9.0-rc7-syzkaller-00023-g6d7ddd805123 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:rcu_read_lock include/linux/rcupdate.h:782 [inline]
RIP: 0010:unix_write_space+0x4e/0x370 net/unix/af_unix.c:543
Code: c7 a0 4d 33 8e 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 41 56 e8 41 37 5d f7 48 83 c4 08 e8 18 38 62 01 89 c3 31 ff 89 c6 <e8> 7d bf 80 f7 85 db 74 10 e8 04 0e 67 f7 84 c0 74 0e e8 2b bb 80
RSP: 0018:ffffc9000319f788 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffff88807d22da00
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000001d03 R08: ffffffff92efe507 R09: 1ffffffff25dfca0
R10: dffffc0000000000 R11: fffffbfff25dfca1 R12: ffff88807d18c800
R13: 00000000000002ff R14: ffffffff8a154c22 R15: ffff88807d18c800
FS:  00007fe4aca62380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffc4ed7a78 CR3: 000000002db8c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 sock_wfree+0x1bc/0x620 net/core/sock.c:2482
 unix_destruct_scm+0x2e7/0x350 net/unix/af_unix.c:1881
 skb_release_head_state+0x100/0x250 net/core/skbuff.c:1188
 skb_release_all net/core/skbuff.c:1200 [inline]
 __kfree_skb net/core/skbuff.c:1216 [inline]
 consume_skb+0x7b/0x160 net/core/skbuff.c:1432
 __unix_dgram_recvmsg+0xe2d/0x1450 net/unix/af_unix.c:2514
 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
 call_read_iter include/linux/fs.h:2104 [inline]
 new_sync_read fs/read_write.c:395 [inline]
 vfs_read+0x97b/0xb70 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+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe4acbb6b6a
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:00007fff1d27ae08 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fe4acbb6b6a
RDX: 00000000000000ff RSI: 000055d0ab71a950 RDI: 0000000000000000
RBP: 000055d0ab71a910 R08: 0000000000000001 R09: 0000000000000000
R10: 00007fe4acd553a3 R11: 0000000000000246 R12: 000055d0ab71a99d
R13: 000055d0ab71a950 R14: 0000000000000000 R15: 00007fe4acd99a80
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/08 23:04 upstream 6d7ddd805123 20bf80e1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_page_mkwrite
* Struck through repros no longer work on HEAD.