INFO: task hung in copy_process (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12d4cba4480000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=a2a2663eb220d8b848b2
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/98c0bdb4abb3/disk-3f8a27f9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ea228ff02669/vmlinux-3f8a27f9.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a2a266...@syzkaller.appspotmail.com

ieee802154 phy1 wpan1: encryption failed: -22
Bluetooth: hci6: command 0x0406 tx timeout
ieee802154 phy0 wpan0: encryption failed: -22
ieee802154 phy1 wpan1: encryption failed: -22
Bluetooth: hci7: command 0x0406 tx timeout
INFO: task kthreadd:2 blocked for more than 140 seconds.
Not tainted 4.19.211-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kthreadd D28264 2 0 0x80000000
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x887/0x2040 kernel/sched/core.c:3517
schedule+0x8d/0x1b0 kernel/sched/core.c:3561
__rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline]
rwsem_down_read_failed+0x20a/0x390 kernel/locking/rwsem-xadd.c:309
call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94
__down_read arch/x86/include/asm/rwsem.h:83 [inline]
__percpu_down_read kernel/locking/percpu-rwsem.c:85 [inline]
__percpu_down_read+0xba/0x130 kernel/locking/percpu-rwsem.c:41
percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline]
percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:698 [inline]
copy_process.part.0+0x6439/0x8260 kernel/fork.c:1974
copy_process kernel/fork.c:1710 [inline]
_do_fork+0x22f/0xf30 kernel/fork.c:2219
kernel_thread+0x2f/0x40 kernel/fork.c:2278
create_kthread kernel/kthread.c:282 [inline]
kthreadd+0x544/0x7b0 kernel/kthread.c:625
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
INFO: task kworker/u4:0:7 blocked for more than 140 seconds.
Not tainted 4.19.211-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:0 D25672 7 2 0x80000000
Workqueue: events_unbound call_usermodehelper_exec_work
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x887/0x2040 kernel/sched/core.c:3517
schedule+0x8d/0x1b0 kernel/sched/core.c:3561
__rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline]
rwsem_down_read_failed+0x20a/0x390 kernel/locking/rwsem-xadd.c:309
call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94
__down_read arch/x86/include/asm/rwsem.h:83 [inline]
__percpu_down_read kernel/locking/percpu-rwsem.c:85 [inline]
__percpu_down_read+0xba/0x130 kernel/locking/percpu-rwsem.c:41
percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline]
percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:698 [inline]
copy_process.part.0+0x6439/0x8260 kernel/fork.c:1974
copy_process kernel/fork.c:1710 [inline]
_do_fork+0x22f/0xf30 kernel/fork.c:2219
kernel_thread+0x2f/0x40 kernel/fork.c:2278
call_usermodehelper_exec_work kernel/umh.c:199 [inline]
call_usermodehelper_exec_work+0x16d/0x260 kernel/umh.c:185
process_one_work+0x864/0x1570 kernel/workqueue.c:2153
worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
INFO: task kworker/u4:4:2889 blocked for more than 140 seconds.
Not tainted 4.19.211-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:4 D26112 2889 2 0x80000000
Workqueue: events_unbound call_usermodehelper_exec_work
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x887/0x2040 kernel/sched/core.c:3517
schedule+0x8d/0x1b0 kernel/sched/core.c:3561
__rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline]
rwsem_down_read_failed+0x20a/0x390 kernel/locking/rwsem-xadd.c:309
call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94
__down_read arch/x86/include/asm/rwsem.h:83 [inline]
__percpu_down_read kernel/locking/percpu-rwsem.c:85 [inline]
__percpu_down_read+0xba/0x130 kernel/locking/percpu-rwsem.c:41
percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline]
percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:698 [inline]
copy_process.part.0+0x6439/0x8260 kernel/fork.c:1974
copy_process kernel/fork.c:1710 [inline]
_do_fork+0x22f/0xf30 kernel/fork.c:2219
kernel_thread+0x2f/0x40 kernel/fork.c:2278
call_usermodehelper_exec_work kernel/umh.c:199 [inline]
call_usermodehelper_exec_work+0x16d/0x260 kernel/umh.c:185
process_one_work+0x864/0x1570 kernel/workqueue.c:2153
worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
INFO: task rs:main Q:Reg:7765 blocked for more than 140 seconds.
Not tainted 4.19.211-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
rs:main Q:Reg D27680 7765 1 0x00000000
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x887/0x2040 kernel/sched/core.c:3517
schedule+0x8d/0x1b0 kernel/sched/core.c:3561
io_schedule+0xb5/0x120 kernel/sched/core.c:5181
wait_on_page_bit_common mm/filemap.c:1123 [inline]
__lock_page+0x316/0x460 mm/filemap.c:1296
lock_page include/linux/pagemap.h:484 [inline]
pagecache_get_page+0x673/0xd50 mm/filemap.c:1577
grab_cache_page_write_begin+0x6a/0xa0 mm/filemap.c:3120
ext4_da_write_begin+0x2ba/0x10e0 fs/ext4/inode.c:3075
generic_perform_write+0x1f8/0x4d0 mm/filemap.c:3170
__generic_file_write_iter+0x24b/0x610 mm/filemap.c:3295
ext4_file_write_iter+0x2fe/0xf20 fs/ext4/file.c:272
call_write_iter include/linux/fs.h:1821 [inline]
new_sync_write fs/read_write.c:474 [inline]
__vfs_write+0x51b/0x770 fs/read_write.c:487
vfs_write+0x1f3/0x540 fs/read_write.c:549
ksys_write+0x12b/0x2a0 fs/read_write.c:599
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f4571ad91cd
Code: c2 20 00 00 75 10 b8 01 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ae fc ff ff 48 89 04 24 b8 01 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 f7 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007f456f094590 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f45640210b0 RCX: 00007f4571ad91cd
RDX: 000000000000005c RSI: 00007f45640210b0 RDI: 0000000000000006
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 00007f4564020e30
R13: 00007f456f0945b0 R14: 000055f7d7200360 R15: 000000000000005c
INFO: task kworker/u4:9:18308 blocked for more than 140 seconds.
Not tainted 4.19.211-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:9 D26624 18308 2 0x80000000
Workqueue: events_unbound call_usermodehelper_exec_work
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x887/0x2040 kernel/sched/core.c:3517
schedule+0x8d/0x1b0 kernel/sched/core.c:3561
__rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline]
rwsem_down_read_failed+0x20a/0x390 kernel/locking/rwsem-xadd.c:309
call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94
__down_read arch/x86/include/asm/rwsem.h:83 [inline]
__percpu_down_read kernel/locking/percpu-rwsem.c:85 [inline]
__percpu_down_read+0xba/0x130 kernel/locking/percpu-rwsem.c:41
percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline]
percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:698 [inline]
copy_process.part.0+0x6439/0x8260 kernel/fork.c:1974
copy_process kernel/fork.c:1710 [inline]
_do_fork+0x22f/0xf30 kernel/fork.c:2219
kernel_thread+0x2f/0x40 kernel/fork.c:2278
call_usermodehelper_exec_work kernel/umh.c:199 [inline]
call_usermodehelper_exec_work+0x16d/0x260 kernel/umh.c:185
process_one_work+0x864/0x1570 kernel/workqueue.c:2153
worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
INFO: task syz-executor.4:27855 blocked for more than 140 seconds.
Not tainted 4.19.211-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4 D29448 27855 27851 0x80000000
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x887/0x2040 kernel/sched/core.c:3517
schedule+0x8d/0x1b0 kernel/sched/core.c:3561
__rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline]
rwsem_down_read_failed+0x20a/0x390 kernel/locking/rwsem-xadd.c:309
call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94
__down_read arch/x86/include/asm/rwsem.h:83 [inline]
__percpu_down_read kernel/locking/percpu-rwsem.c:85 [inline]
__percpu_down_read+0xba/0x130 kernel/locking/percpu-rwsem.c:41
percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline]
percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:698 [inline]
exit_signals+0x4ae/0x730 kernel/signal.c:2674
do_exit+0x2ed/0x2be0 kernel/exit.c:826
__do_sys_exit kernel/exit.c:936 [inline]
__se_sys_exit kernel/exit.c:934 [inline]
__x64_sys_exit+0x3e/0x50 kernel/exit.c:934
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f998ea2cd0e
Code: Bad RIP value.
RSP: 002b:00007f998d7f1240 EFLAGS: 00000246 ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 00007f998d7f1700 RCX: 00007f998ea2cd0e
RDX: 000000000000003c RSI: 00000000007fc000 RDI: 0000000000000000
RBP: 00007f998cff1000 R08: 0000000000000000 R09: 00007f998d7f1700
R10: 00007f998d7f19d0 R11: 0000000000000246 R12: 00007ffe8bdb68be
R13: 00007ffe8bdb68bf R14: 00007f998d7f1300 R15: 0000000000802000

Showing all locks held in the system:
5 locks held by systemd/1:
1 lock held by kthreadd/2:
#0: 00000000b541111d (&cgroup_threadgroup_rwsem){++++}, at: copy_process kernel/fork.c:1710 [inline]
#0: 00000000b541111d (&cgroup_threadgroup_rwsem){++++}, at: _do_fork+0x22f/0xf30 kernel/fork.c:2219
3 locks held by kworker/u4:0/7:
#0: 000000005ed74464 ((wq_completion)"events_unbound"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124
#1: 00000000bdfbbab4 ((work_completion)(&sub_info->work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128
#2: 00000000b541111d (&cgroup_threadgroup_rwsem){++++}, at: copy_process kernel/fork.c:1710 [inline]
#2: 00000000b541111d (&cgroup_threadgroup_rwsem){++++}, at: _do_fork+0x22f/0xf30 kernel/fork.c:2219
6 locks held by kworker/u4:1/23:
3 locks held by kworker/u4:3/206:
1 lock held by khungtaskd/1570:
#0: 0000000083131b6f (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441
3 locks held by kworker/u4:4/2889:
#0: 000000005ed74464 ((wq_completion)"events_unbound"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124
#1: 000000002339cffa ((work_completion)(&sub_info->work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128
#2: 00000000b541111d (&cgroup_threadgroup_rwsem){++++}, at: copy_process kernel/fork.c:1710 [inline]
#2: 00000000b541111d (&cgroup_threadgroup_rwsem){++++}, at: _do_fork+0x22f/0xf30 kernel/fork.c:2219
1 lock held by kworker/dying/3686:
#0: 00000000b541111d (&cgroup_threadgroup_rwsem){++++}, at: do_exit+0x2ed/0x2be0 kernel/exit.c:826
3 locks held by bat_events/4606:
1 lock held by systemd-journal/4684:
1 lock held by systemd-timesyn/6162:
1 lock held by kworker/dying/6163:
#0: 00000000b541111d (&cgroup_threadgroup_rwsem){++++}, at: do_exit+0x2ed/0x2be0 kernel/exit.c:826
1 lock held by in:imklog/7764:
#0: 000000000af1711e (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767
3 locks held by rs:main Q:Reg/7765:
#0: 00000000f9de7254 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767
#1: 00000000cfaa26dd (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2779 [inline]
#1: 00000000cfaa26dd (sb_writers#3){.+.+}, at: vfs_write+0x463/0x540 fs/read_write.c:548
#2: 00000000523f2b2b (&sb->s_type->i_mutex_key#10){++++}, at: inode_trylock include/linux/fs.h:768 [inline]
#2: 00000000523f2b2b (&sb->s_type->i_mutex_key#10){++++}, at: ext4_file_write_iter+0x21f/0xf20 fs/ext4/file.c:238
3 locks held by kworker/u4:7/9559:
3 locks held by kworker/u4:9/18308:
#0: 000000005ed74464 ((wq_completion)"events_unbound"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124
#1: 000000004cff3a5f ((work_completion)(&sub_info->work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128
#2: 00000000b541111d (&cgroup_threadgroup_rwsem){++++}, at: copy_process kernel/fork.c:1710 [inline]
#2: 00000000b541111d (&cgroup_threadgroup_rwsem){++++}, at: _do_fork+0x22f/0xf30 kernel/fork.c:2219
1 lock held by kworker/dying/25511:
#0: 00000000b541111d (&cgroup_threadgroup_rwsem){++++}, at: do_exit+0x2ed/0x2be0 kernel/exit.c:826
2 locks held by syz-executor.2/27498:
3 locks held by syz-executor.4/27550:
1 lock held by syz-executor.2/27587:
#0: 00000000b541111d (&cgroup_threadgroup_rwsem){++++}, at: do_exit+0x2ed/0x2be0 kernel/exit.c:826
1 lock held by syz-executor.2/27840:
#0: 00000000b541111d (&cgroup_threadgroup_rwsem){++++}, at: do_exit+0x2ed/0x2be0 kernel/exit.c:826
1 lock held by syz-executor.4/27851:
#0: 00000000b541111d (&cgroup_threadgroup_rwsem){++++}, at: do_exit+0x2ed/0x2be0 kernel/exit.c:826
1 lock held by syz-executor.4/27855:
#0: 00000000b541111d (&cgroup_threadgroup_rwsem){++++}, at: do_exit+0x2ed/0x2be0 kernel/exit.c:826
2 locks held by (d-rfkill)/27856:

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

NMI backtrace for cpu 0
CPU: 0 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
watchdog+0x991/0xe60 kernel/hung_task.c:287
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4606 Comm: bat_events Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: bat_events batadv_tt_purge
RIP: 0010:preempt_count_add+0x18/0x190 kernel/sched/core.c:3230
Code: 5a ff ff ff 48 c7 c7 40 f7 36 8d e8 b2 f3 56 00 eb ab 48 b8 00 00 00 00 00 fc ff df 55 89 fd 53 48 c7 c3 60 37 24 8d 48 89 da <48> c1 ea 03 0f b6 14 02 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 08 84
RSP: 0018:ffff8880ba1078c0 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffffffff8d243760 RCX: 0000000000000006
RDX: ffffffff8d243760 RSI: ffff8880ba107868 RDI: 0000000000000001
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000001
R10: ffff8880ba107a67 R11: 0000000000074071 R12: ffff8880ba107a50
R13: 0000000000000000 R14: ffff8880ba107a08 R15: 00000000000000e8
FS: 0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561fcc9cc9c8 CR3: 00000000b49bf000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
unwind_next_frame+0x135/0x1400 arch/x86/kernel/unwind_orc.c:407
__save_stack_trace+0x9f/0x190 arch/x86/kernel/stacktrace.c:44
save_stack mm/kasan/kasan.c:448 [inline]
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:553
slab_post_alloc_hook mm/slab.h:445 [inline]
slab_alloc_node mm/slab.c:3340 [inline]
kmem_cache_alloc_node+0x133/0x3b0 mm/slab.c:3647
__alloc_skb+0x71/0x560 net/core/skbuff.c:193
alloc_skb include/linux/skbuff.h:995 [inline]
bcm_can_tx+0x259/0x800 net/can/bcm.c:287
bcm_tx_timeout_tsklet+0x1f0/0x3a0 net/can/bcm.c:414
tasklet_action_common.constprop.0+0x265/0x360 kernel/softirq.c:522
__do_softirq+0x265/0x980 kernel/softirq.c:292
do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1092
</IRQ>
do_softirq.part.0+0x160/0x1c0 kernel/softirq.c:336
do_softirq kernel/softirq.c:328 [inline]
__local_bh_enable_ip+0x20e/0x270 kernel/softirq.c:189
spin_unlock_bh include/linux/spinlock.h:374 [inline]
batadv_tt_local_purge+0x278/0x370 net/batman-adv/translation-table.c:1456
batadv_tt_purge+0x2c/0xa00 net/batman-adv/translation-table.c:3811
process_one_work+0x864/0x1570 kernel/workqueue.c:2153
process_scheduled_works kernel/workqueue.c:2212 [inline]
rescuer_thread+0x5b4/0xce0 kernel/workqueue.c:2403
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.