WARNING: syz-executor still has locks held!

[syzbot <syzbot+b70f2aabc707c69c9239@syzkaller.appspotmail.com>]

Hello,

syzbot found the following crash on:

HEAD commit:    7c98a4261827 Merge tag 'ceph-for-4.20-rc4' of https://gith..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12d81015400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=73e2bc0cb6463446
dashboard link: https://syzkaller.appspot.com/bug?extid=b70f2aabc707c69c9239
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16c9e26d400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14e1234d400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+b70f2aabc707c69c9239@syzkaller.appspotmail.com

audit: type=1400 audit(1543059836.603:35): avc:  denied  { map } for   
pid=6203 comm="bash" path="/bin/bash" dev="sda1" ino=1457  
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023  
tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1
audit: type=1400 audit(1543059843.273:36): avc:  denied  { map } for   
pid=6217 comm="syz-executor552" path="/root/syz-executor552394561"  
dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023  
tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1

====================================
WARNING: syz-executor552/6218 still has locks held!
4.20.0-rc3+ #127 Not tainted
------------------------------------
1 lock held by syz-executor552/6218:
  #0: 000000004754a9eb (&sig->cred_guard_mutex){+.+.}, at:  
prepare_bprm_creds+0x53/0x120 fs/exec.c:1405

stack backtrace:
CPU: 0 PID: 6218 Comm: syz-executor552 Not tainted 4.20.0-rc3+ #127
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
  print_held_locks_bug kernel/locking/lockdep.c:4362 [inline]
  debug_check_no_locks_held.cold.49+0x93/0x9f kernel/locking/lockdep.c:4368
  try_to_freeze include/linux/freezer.h:66 [inline]
  freezer_count include/linux/freezer.h:128 [inline]
  freezable_schedule include/linux/freezer.h:173 [inline]
  de_thread fs/exec.c:1115 [inline]
  flush_old_exec+0x1ea2/0x2480 fs/exec.c:1262
  load_elf_binary+0xa39/0x5620 fs/binfmt_elf.c:869
  search_binary_handler+0x17d/0x570 fs/exec.c:1654
  exec_binprm fs/exec.c:1696 [inline]
  __do_execve_file.isra.33+0x1661/0x25d0 fs/exec.c:1820
  do_execveat_common fs/exec.c:1867 [inline]
  do_execveat fs/exec.c:1895 [inline]
  __do_sys_execveat fs/exec.c:1976 [inline]
  __se_sys_execveat fs/exec.c:1968 [inline]
  __x64_sys_execveat+0xed/0x130 fs/exec.c:1968
  do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x445639
Code: e8 ec b8 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7  
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff  
ff 0f 83 8b 12 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f5efaee7d18 EFLAGS: 00000246 ORIG_RAX: 0000000000000142
RAX: ffffffffffffffda RBX: 00000000006dac28 RCX: 0000000000445639
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 00000000006dac20 R08: 0000000000001000 R09: 65732f636f72702f
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5efaee7d20
R13: 00000000006dac2c R14: 0000000020000280 R15: 00000000006dad2c


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