syzbot


INFO: task hung in pipe_write (5)

Status: auto-obsoleted due to no activity on 2025/02/15 05:49
Subsystems: fs
[Documentation on labels]
First crash: 137d, last: 96d
Similar bugs (14)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in pipe_write (3) fs 1 1853d 1853d 0/28 auto-closed as invalid on 2020/04/25 05:37
android-44 INFO: task hung in pipe_write 1 2268d 2140d 0/2 auto-closed as invalid on 2019/06/05 06:19
upstream INFO: task hung in rtnetlink_rcv_msg net C inconclusive inconclusive 1970 227d 2191d 26/28 fixed on 2024/07/09 19:14
upstream INFO: task hung in pipe_write (2) ext4 C done 6 1982d 1982d 0/28 closed as invalid on 2019/09/28 02:25
upstream INFO: task hung in pipe_write fs 8 2213d 2327d 0/28 auto-closed as invalid on 2019/07/30 21:09
linux-4.14 INFO: task hung in pipe_write C 1 734d 851d 0/1 upstream: reported C repro on 2022/10/24 05:45
android-44 INFO: task hung in pipe_write (2) 1 1908d 1908d 0/2 auto-closed as invalid on 2020/03/31 01:26
android-49 INFO: task hung in pipe_write C 3 1934d 2140d 0/3 public: reported C repro on 2019/04/14 08:51
linux-4.19 INFO: task hung in pipe_write C error 13 821d 1720d 0/1 upstream: reported C repro on 2020/06/07 01:40
upstream INFO: task hung in pipe_write (6) netfs C done 4 5h29m 3d14h 0/28 upstream: reported C repro on 2025/02/18 09:37
upstream INFO: task hung in pipe_write (4) fs syz error 7 1120d 1667d 0/28 auto-obsoleted due to no activity on 2022/10/22 17:00
android-414 INFO: task hung in pipe_write 1 1957d 1957d 0/1 auto-closed as invalid on 2020/02/11 22:17
upstream INFO: task can't die in pipe_write (2) fs 1 1220d 1216d 0/28 auto-closed as invalid on 2021/12/19 10:46
upstream INFO: task can't die in pipe_write fs 1 1294d 1267d 0/28 auto-closed as invalid on 2021/10/06 11:40

Sample crash report:
INFO: task syz-executor:5836 blocked for more than 143 seconds.
      Not tainted 6.12.0-rc7-syzkaller-00212-g4a5df3796467 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22752 pid:5836  tgid:5836  ppid:1      flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5328 [inline]
 __schedule+0xe55/0x5740 kernel/sched/core.c:6693
 __schedule_loop kernel/sched/core.c:6770 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6785
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6842
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752
 pipe_write+0x166/0x1b30 fs/pipe.c:455
 new_sync_write fs/read_write.c:590 [inline]
 vfs_write+0x5ae/0x1150 fs/read_write.c:683
 ksys_write+0x1fa/0x260 fs/read_write.c:736
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd88157d1ff
RSP: 002b:00007ffd24e3bdf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000016 RCX: 00007fd88157d1ff
RDX: 0000000000000016 RSI: 00007ffd24e3bff0 RDI: 0000000000000002
RBP: 00007ffd24e3bff0 R08: 0000000000000000 R09: 00007fd8823de080
R10: 00000000ffffffff R11: 0000000000000293 R12: 0000000000000016
R13: 00007fd88170c620 R14: 0000000000000016 R15: 00007fd88170dc80
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6720
2 locks held by getty/5596:
 #0: ffff88814dccd0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5826:
 #0: ffff88807f813068 (&pipe->mutex){+.+.}-{3:3}, at: pipe_release+0x44/0x320 fs/pipe.c:727
1 lock held by syz-executor/5836:
 #0: ffff88807f813068 (&pipe->mutex){+.+.}-{3:3}, at: pipe_write+0x166/0x1b30 fs/pipe.c:455
1 lock held by syz.1.466/8216:
 #0: ffff88807f813068 (&pipe->mutex){+.+.}-{3:3}, at: pipe_lock fs/pipe.c:92 [inline]
 #0: ffff88807f813068 (&pipe->mutex){+.+.}-{3:3}, at: pipe_lock+0x64/0x80 fs/pipe.c:89

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc7-syzkaller-00212-g4a5df3796467 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 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+0xf0c/0x1240 kernel/hung_task.c:379
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 7432 Comm: kworker/u8:27 Not tainted 6.12.0-rc7-syzkaller-00212-g4a5df3796467 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__lock_acquire+0x386/0x3ce0 kernel/locking/lockdep.c:5139
Code: 45 01 e4 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 bc 2b 00 00 41 83 bf c4 0a 00 00 01 49 8d 7d 24 44 89 e0 44 89 da 83 d8 ff <c1> e3 0f c1 e0 0d c1 e2 10 0f b7 db 81 e2 00 00 03 00 09 d8 41 c1
RSP: 0018:ffffc90015b07960 EFLAGS: 00000057
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffff1100c2cc165
RDX: 0000000000000002 RSI: 0000000000000022 RDI: ffff888061660b54
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000000a R11: 0000000000000002 R12: 0000000000000000
R13: ffff888061660b30 R14: 0000000000000022 R15: ffff888061660000
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055fe0c490600 CR3: 000000000db7c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825
 rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 rcu_read_lock include/linux/rcupdate.h:849 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0x16a/0x1060 net/batman-adv/network-coding.c:719
 process_one_work+0x958/0x1b30 kernel/workqueue.c:3229
 process_scheduled_works kernel/workqueue.c:3310 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/17 05:40 upstream 4a5df3796467 cfe3a04a .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in pipe_write
2024/10/26 19:04 upstream 850925a8133c 65e8686b .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in pipe_write
2024/10/07 16:08 upstream 8cf0b93919e1 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in pipe_write
2024/10/17 16:59 upstream c964ced77262 666f77ed .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in pipe_write
* Struck through repros no longer work on HEAD.