INFO: task hung in tls_sw_free_resources_tx

INFO: task hung in tls_sw_free_resources_tx

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    6915bf3b002b net: phy: don't allow __set_phy_supported to ..
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=177085a3400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=28ecefa8a6e10719
dashboard link: https://syzkaller.appspot.com/bug?extid=503339bf3c9053b8a7fc
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11e6996d400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=117e2125400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+503339bf3c9053b8a7fc@syzkaller.appspotmail.com

TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending  
cookies.  Check SNMP counters.
TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending  
cookies.  Check SNMP counters.
TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending  
cookies.  Check SNMP counters.
INFO: task syz-executor852:6003 blocked for more than 140 seconds.
       Not tainted 4.20.0-rc4+ #324
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor852 D20984  6003   5985 0x00000004
Call Trace:
  context_switch kernel/sched/core.c:2831 [inline]
  __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472
  schedule+0xfe/0x460 kernel/sched/core.c:3516
  schedule_timeout+0x1cc/0x260 kernel/time/timer.c:1780
  do_wait_for_common kernel/sched/completion.c:83 [inline]
  __wait_for_common kernel/sched/completion.c:104 [inline]
  wait_for_common kernel/sched/completion.c:115 [inline]
  wait_for_completion+0x427/0x8a0 kernel/sched/completion.c:136
  crypto_wait_req include/linux/crypto.h:583 [inline]
  tls_sw_free_resources_tx+0x52b/0xcf0 net/tls/tls_sw.c:1774
  tls_sk_proto_close+0x602/0x750 net/tls/tls_main.c:278
  inet_release+0x104/0x1f0 net/ipv4/af_inet.c:428
  inet6_release+0x50/0x70 net/ipv6/af_inet6.c:458
  __sock_release+0xd7/0x250 net/socket.c:579
  sock_close+0x19/0x20 net/socket.c:1141
  __fput+0x385/0xa30 fs/file_table.c:278
  ____fput+0x15/0x20 fs/file_table.c:309
  task_work_run+0x1e8/0x2a0 kernel/task_work.c:113
  tracehook_notify_resume include/linux/tracehook.h:188 [inline]
  exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166
  prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
  syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
  do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x400fe0
Code: 01 f0 ff ff 0f 83 b0 0a 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f  
44 00 00 83 3d ed 16 2d 00 00 75 14 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff  
ff 0f 83 84 0a 00 00 c3 48 83 ec 08 e8 3a 01 00 00
RSP: 002b:00007ffe30095a88 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000400fe0
RDX: 0000000000000058 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000067edd
R13: 0000000000401f80 R14: 0000000000000000 R15: 0000000000000000

Showing all locks held in the system:
1 lock held by khungtaskd/1020:
  #0: 0000000034ca4b1e (rcu_read_lock){....}, at:  
debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379
1 lock held by rsyslogd/5866:
  #0: 00000000f2b3f94d (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200  
fs/file.c:766
2 locks held by getty/5956:
  #0: 000000000ac99831 (&tty->ldisc_sem){++++}, at:  
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
  #1: 00000000d09933e4 (&ldata->atomic_read_lock){+.+.}, at:  
n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/5957:
  #0: 000000005f0193c3 (&tty->ldisc_sem){++++}, at:  
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
  #1: 00000000f88a15c8 (&ldata->atomic_read_lock){+.+.}, at:  
n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/5958:
  #0: 00000000794f4a79 (&tty->ldisc_sem){++++}, at:  
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
  #1: 000000002fefcb05 (&ldata->atomic_read_lock){+.+.}, at:  
n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/5959:
  #0: 0000000074eb97d6 (&tty->ldisc_sem){++++}, at:  
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
  #1: 0000000065ce552e (&ldata->atomic_read_lock){+.+.}, at:  
n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/5960:
  #0: 00000000c84b7e95 (&tty->ldisc_sem){++++}, at:  
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
  #1: 0000000020f1a59d (&ldata->atomic_read_lock){+.+.}, at:  
n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/5961:
  #0: 00000000c90dcbd8 (&tty->ldisc_sem){++++}, at:  
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
  #1: 00000000409d1c2e (&ldata->atomic_read_lock){+.+.}, at:  
n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/5962:
  #0: 000000006f39f77f (&tty->ldisc_sem){++++}, at:  
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
  #1: 00000000c23bd515 (&ldata->atomic_read_lock){+.+.}, at:  
n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by syz-executor852/6003:
  #0: 000000005aa3007c (&sb->s_type->i_mutex_key#11){+.+.}, at: inode_lock  
include/linux/fs.h:757 [inline]
  #0: 000000005aa3007c (&sb->s_type->i_mutex_key#11){+.+.}, at:  
__sock_release+0x8b/0x250 net/socket.c:578
  #1: 0000000097a7edc0 (sk_lock-AF_INET6){+.+.}, at: lock_sock  
include/net/sock.h:1492 [inline]
  #1: 0000000097a7edc0 (sk_lock-AF_INET6){+.+.}, at:  
tls_sk_proto_close+0xf5/0x750 net/tls/tls_main.c:262

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

NMI backtrace for cpu 0
CPU: 0 PID: 1020 Comm: khungtaskd Not tainted 4.20.0-rc4+ #324
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x244/0x39d lib/dump_stack.c:113
  nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101
  nmi_trigger_cpumask_backtrace+0x1e8/0x22a lib/nmi_backtrace.c:62
  arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
  trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
  check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
  watchdog+0xb51/0x1060 kernel/hung_task.c:289
  kthread+0x35a/0x440 kernel/kthread.c:246
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10  
arch/x86/include/asm/irqflags.h:57


---
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Re: INFO: task hung in tls_sw_free_resources_tx

[syzbot]

syzbot has bisected this bug to:

commit 3c4d7559159bfe1e3b94df3a657b2cda3a34e218
Author: Dave Watson <davejwatson@fb.com>
Date:   Wed Jun 14 18:37:39 2017 +0000

     tls: kernel TLS support

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10c2d407200000
start commit:   6915bf3b net: phy: don't allow __set_phy_supported to add ..
git tree:       net-next
final crash:    https://syzkaller.appspot.com/x/report.txt?x=12c2d407200000
console output: https://syzkaller.appspot.com/x/log.txt?x=14c2d407200000
kernel config:  https://syzkaller.appspot.com/x/.config?x=28ecefa8a6e10719
dashboard link: https://syzkaller.appspot.com/bug?extid=503339bf3c9053b8a7fc
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11e6996d400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=117e2125400000

Reported-by: syzbot+503339bf3c9053b8a7fc@syzkaller.appspotmail.com
Fixes: 3c4d7559159b ("tls: kernel TLS support")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Re: INFO: task hung in tls_sw_free_resources_tx

[Jakub Kicinski]

On Tue, 04 Dec 2018 00:48:02 -0800, syzbot wrote:
> Hello,
> 
> syzbot found the following crash on:
> 
> HEAD commit:    6915bf3b002b net: phy: don't allow __set_phy_supported to ..
> git tree:       net-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=177085a3400000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=28ecefa8a6e10719
> dashboard link: https://syzkaller.appspot.com/bug?extid=503339bf3c9053b8a7fc
> compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11e6996d400000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=117e2125400000
> 
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+503339bf3c9053b8a7fc@syzkaller.appspotmail.com

#syz dup: INFO: task hung in aead_recvmsg