------------[ cut here ]------------
WARNING: CPU: 1 PID: 27014 at fs/namespace.c:1187 mntput_no_expire+0xada/0xcd0 fs/namespace.c:1187
Modules linked in:
CPU: 1 PID: 27014 Comm: syz-executor.5 Not tainted 5.15.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:mntput_no_expire+0xada/0xcd0 fs/namespace.c:1187
Code: 30 84 c0 0f 84 b9 fe ff ff 3c 03 0f 8f b1 fe ff ff 4c 89 44 24 10 e8 05 f9 eb ff 4c 8b 44 24 10 e9 9d fe ff ff e8 06 86 a4 ff <0f> 0b e9 19 fd ff ff e8 fa 85 a4 ff e8 a5 7d 66 07 31 ff 89 c5 89
RSP: 0018:ffffc90008a4fc18 EFLAGS: 00010246
RAX: 0000000000040000 RBX: 1ffff92001149f89 RCX: ffffc90013f06000
RDX: 0000000000040000 RSI: ffffffff81d2649a RDI: 0000000000000003
RBP: ffff888097fd7980 R08: 0000000000000000 R09: ffffffff8fd0d9ef
R10: ffffffff81d261b1 R11: 0000000000000000 R12: 0000000000000008
R13: ffffc90008a4fc68 R14: 00000000ffffffff R15: 0000000000000002
FS:  00007fa1c55ed700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d82b000 CR3: 0000000091489000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 mntput fs/namespace.c:1233 [inline]
 namespace_unlock+0x26b/0x410 fs/namespace.c:1452
 drop_collected_mounts fs/namespace.c:1935 [inline]
 put_mnt_ns fs/namespace.c:4344 [inline]
 put_mnt_ns+0x106/0x140 fs/namespace.c:4340
 create_new_namespaces+0x6d1/0xb20 kernel/nsproxy.c:141
 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x445/0x920 kernel/fork.c:3077
 __do_sys_unshare kernel/fork.c:3151 [inline]
 __se_sys_unshare kernel/fork.c:3149 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3149
 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: 0033:0x7fa1c8077a39
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:00007fa1c55ed188 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fa1c817af60 RCX: 00007fa1c8077a39
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006c060000
RBP: 00007fa1c80d1e8f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe2bd55f7f R14: 00007fa1c55ed300 R15: 0000000000022000