------------[ cut here ]------------
WARNING: CPU: 0 PID: 457 at fs/namespace.c:1186 mntput_no_expire+0xade/0xcc0 fs/namespace.c:1186
Modules linked in:
CPU: 0 PID: 457 Comm: syz-executor.1 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:mntput_no_expire+0xade/0xcc0 fs/namespace.c:1186
Code: ff 48 c7 c2 e0 5a 99 89 be d1 02 00 00 48 c7 c7 a0 5a 99 89 c6 05 b5 25 07 0c 01 e8 78 67 0f 07 e9 3f fd ff ff e8 72 34 a6 ff <0f> 0b e9 fc fc ff ff e8 66 34 a6 ff e8 b1 11 92 ff 31 ff 89 c5 89
RSP: 0018:ffffc90001b6fc18 EFLAGS: 00010246
RAX: 0000000000040000 RBX: 1ffff9200036df89 RCX: ffffc9000bbeb000
RDX: 0000000000040000 RSI: ffffffff81cf500e RDI: 0000000000000003
RBP: ffff8880125f8d80 R08: 0000000000000000 R09: ffffffff904958af
R10: ffffffff81cf4d08 R11: 0000000000000000 R12: 0000000000000008
R13: ffffc90001b6fc68 R14: 00000000ffffffff R15: 0000000000000002
FS:  00007f0830b04700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000002b2c848 CR3: 00000000a69c2000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 mntput fs/namespace.c:1232 [inline]
 namespace_unlock+0x26b/0x410 fs/namespace.c:1451
 drop_collected_mounts fs/namespace.c:1938 [inline]
 put_mnt_ns fs/namespace.c:4259 [inline]
 put_mnt_ns+0x106/0x140 fs/namespace.c:4255
 create_new_namespaces+0x6d1/0xb20 kernel/nsproxy.c:141
 unshare_nsproxy_namespaces+0xbd/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x445/0x920 kernel/fork.c:3002
 __do_sys_unshare kernel/fork.c:3076 [inline]
 __se_sys_unshare kernel/fork.c:3074 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3074
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0830b04188 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006c060000
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffdc9eaf19f R14: 00007f0830b04300 R15: 0000000000022000