syzbot


INFO: task hung in pipe_release (6)

Status: upstream: reported syz repro on 2025/02/27 19:55
Subsystems: bcachefs
[Documentation on labels]
Reported-by: syzbot+23e4a7772eb9a9715b85@syzkaller.appspotmail.com
First crash: 80d, last: 14h05m
Cause bisection: introduced by (bisect log) :
commit 1d16c605cc55ef26f0c65b362665a6c99080ccbc
Author: Kent Overstreet <kent.overstreet@linux.dev>
Date: Thu Nov 9 19:22:46 2023 +0000

  bcachefs: Disk space accounting rewrite

Crash: INFO: task hung in __closure_sync (log)
Repro: syz .config
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bcachefs?] INFO: task hung in pipe_release (6) 0 (1) 2025/02/27 19:55
Similar bugs (13)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-414 INFO: task hung in pipe_release 1 2120d 2120d 0/1 auto-closed as invalid on 2019/11/24 16:38
upstream INFO: task hung in pipe_release (5) fs 160 135d 244d 0/28 auto-obsoleted due to no activity on 2025/02/21 02:48
upstream INFO: task hung in pipe_release (2) ext4 syz done 3 1717d 1748d 15/28 fixed on 2020/09/25 01:17
android-49 INFO: task hung in pipe_release (2) 1 2084d 2084d 0/3 auto-closed as invalid on 2019/12/30 22:08
linux-6.1 INFO: task hung in pipe_release 2 202d 261d 0/3 auto-obsoleted due to no activity on 2025/02/03 06:35
upstream INFO: task hung in pipe_release (4) fs C done 51 674d 674d 23/28 fixed on 2023/10/12 12:48
android-49 INFO: task hung in pipe_release 2 2313d 2224d 0/3 auto-closed as invalid on 2019/07/14 20:38
upstream INFO: task hung in pipe_release (3) fs 4 1278d 1391d 0/28 closed as invalid on 2022/02/07 19:19
upstream INFO: task hung in pipe_release fs 2 2210d 2375d 0/28 auto-closed as invalid on 2019/10/25 10:11
linux-4.19 INFO: task hung in pipe_release 1 1513d 1513d 0/1 auto-closed as invalid on 2021/07/23 11:59
linux-5.15 INFO: task hung in pipe_release 2 210d 271d 0/3 auto-obsoleted due to no activity on 2025/01/27 06:00
linux-5.15 INFO: task hung in pipe_release (2) 1 51d 51d 0/3 upstream: reported on 2025/03/26 20:01
upstream INFO: task can't die in pipe_release (2) fs 1 1569d 1565d 0/28 auto-closed as invalid on 2021/03/29 10:10
Last patch testing requests (3)
Created Duration User Patch Repo Result
2025/03/13 03:10 17m retest repro upstream report log
2025/03/13 03:10 17m retest repro upstream report log
2025/03/13 03:10 18m retest repro upstream report log

Sample crash report:
INFO: task syz-executor:5823 blocked for more than 143 seconds.
      Not tainted 6.15.0-rc6-syzkaller-00188-gfee3e843b309 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21624 pid:5823  tgid:5823  ppid:5817   task_flags:0x400100 flags:0x00000002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x168f/0x4c70 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6860
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
 __mutex_lock_common kernel/locking/mutex.c:678 [inline]
 __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:746
 pipe_release+0x48/0x330 fs/pipe.c:728
 __fput+0x449/0xa70 fs/file_table.c:465
 fput_close_sync+0x119/0x200 fs/file_table.c:570
 __do_sys_close fs/open.c:1581 [inline]
 __se_sys_close fs/open.c:1566 [inline]
 __x64_sys_close+0x7f/0x110 fs/open.c:1566
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe99138d5a0
RSP: 002b:00007ffd16e68988 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00005555600a3cb0 RCX: 00007fe99138d5a0
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000021
RBP: 00005555600b1510 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000202 R12: 00007ffd16e689b0
R13: 0000000000000024 R14: 00005555600a3cfc R15: 00005555600a25c8
 </TASK>
INFO: task syz.3.19:6143 blocked for more than 143 seconds.
      Not tainted 6.15.0-rc6-syzkaller-00188-gfee3e843b309 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.19        state:D stack:18520 pid:6143  tgid:6105  ppid:5936   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x168f/0x4c70 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6860
 io_schedule+0x81/0xe0 kernel/sched/core.c:7742
 folio_wait_bit_common+0x6b0/0xb90 mm/filemap.c:1317
 folio_lock include/linux/pagemap.h:1137 [inline]
 invalidate_inode_pages2_range+0x557/0xa80 mm/truncate.c:686
 bch2_write_invalidate_inode_pages_range+0xc5/0x110 fs/bcachefs/fs-io-pagecache.c:68
 bch2_direct_write+0x2abc/0x2d50 fs/bcachefs/fs-io-direct.c:661
 bch2_write_iter+0x18f/0x2b90 fs/bcachefs/fs-io-buffered.c:1072
 iter_file_splice_write+0x937/0x1000 fs/splice.c:738
 do_splice_from fs/splice.c:935 [inline]
 direct_splice_actor+0xfe/0x160 fs/splice.c:1158
 splice_direct_to_actor+0x5a8/0xcc0 fs/splice.c:1102
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0x181/0x270 fs/splice.c:1227
 do_sendfile+0x4da/0x7d0 fs/read_write.c:1368
 __do_sys_sendfile64 fs/read_write.c:1429 [inline]
 __se_sys_sendfile64+0x13e/0x190 fs/read_write.c:1415
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f652298e969
RSP: 002b:00007f6523879038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f6522bb6080 RCX: 00007f652298e969
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000005
RBP: 00007f6522a10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000800000009 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f6522bb6080 R15: 00007fff6000ed08
 </TASK>
INFO: task syz.3.19:6144 blocked for more than 144 seconds.
      Not tainted 6.15.0-rc6-syzkaller-00188-gfee3e843b309 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.19        state:D stack:27424 pid:6144  tgid:6105  ppid:5936   task_flags:0x440140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x168f/0x4c70 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6860
 __bch2_two_state_lock+0x1ea/0x370 fs/bcachefs/two_state_shared_lock.c:7
 bch2_two_state_lock fs/bcachefs/two_state_shared_lock.h:55 [inline]
 bch2_readahead+0x94f/0x1100 fs/bcachefs/fs-io-buffered.c:296
 read_pages+0x177/0x590 mm/readahead.c:160
 page_cache_ra_order+0xa24/0xc70 mm/readahead.c:515
 filemap_get_pages+0x43c/0x1eb0 mm/filemap.c:2591
 filemap_splice_read+0x4fc/0xbc0 mm/filemap.c:2981
 do_splice_read fs/splice.c:979 [inline]
 splice_file_to_pipe+0x270/0x440 fs/splice.c:1289
 do_sendfile+0x475/0x7d0 fs/read_write.c:1374
 __do_sys_sendfile64 fs/read_write.c:1429 [inline]
 __se_sys_sendfile64+0x13e/0x190 fs/read_write.c:1415
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f652298e969
RSP: 002b:00007f6523858038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f6522bb6160 RCX: 00007f652298e969
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000000
RBP: 00007f6522a10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000fff R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f6522bb6160 R15: 00007fff6000ed08
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
1 lock held by klogd/5179:
 #0: ffff8880b88399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605
2 locks held by getty/5578:
 #0: ffff88814da4e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900036e52f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/5823:
 #0: ffff88802fb5dc68 (&pipe->mutex){+.+.}-{4:4}, at: pipe_release+0x48/0x330 fs/pipe.c:728
1 lock held by syz.3.19/6143:
 #0: ffff888031548420 (sb_writers#12){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160 fs/splice.c:1157
2 locks held by syz.3.19/6144:
 #0: ffff88802fb5dc68 (&pipe->mutex){+.+.}-{4:4}, at: splice_file_to_pipe+0x2e/0x440 fs/splice.c:1286
 #1: ffff88805d8c8a80 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:922 [inline]
 #1: ffff88805d8c8a80 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: page_cache_ra_order+0x445/0xc70 mm/readahead.c:491

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc6-syzkaller-00188-gfee3e843b309 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:437
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-rc6-syzkaller-00188-gfee3e843b309 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81
Code: 43 d4 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d a3 bf 18 00 f3 0f 1e fa fb f4 <e9> 18 d4 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8dc07d80 EFLAGS: 000002c6
RAX: d1d2ec82df1bed00 RBX: ffffffff81977048 RCX: d1d2ec82df1bed00
RDX: 0000000000000001 RSI: ffffffff8d738ea1 RDI: ffffffff8bc10660
RBP: ffffffff8dc07ec0 R08: ffff8880b8832b5b R09: 1ffff1101710656b
R10: dffffc0000000000 R11: ffffed101710656c R12: ffffffff8f7dd370
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1b92a48
FS:  0000000000000000(0000) GS:ffff8881260f9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562889937660 CR3: 000000000dd38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:748
 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x1e8/0x510 kernel/sched/idle.c:325
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423
 rest_init+0x2de/0x300 init/main.c:743
 start_kernel+0x470/0x4f0 init/main.c:1099
 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:513
 x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:494
 common_startup_64+0x13e/0x147
 </TASK>

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/16 16:27 upstream fee3e843b309 cfde8269 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs INFO: task hung in pipe_release
2025/02/25 16:45 upstream d082ecbc71e9 d34966d1 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs INFO: task hung in pipe_release
2025/02/25 12:43 upstream d082ecbc71e9 d34966d1 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs INFO: task hung in pipe_release
2025/02/25 10:22 upstream d082ecbc71e9 d34966d1 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs INFO: task hung in pipe_release
2025/02/25 08:10 upstream d082ecbc71e9 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in pipe_release
2025/03/25 22:38 net-next cc04ed502457 89d30d73 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in pipe_release
* Struck through repros no longer work on HEAD.