------------[ cut here ]------------
WARNING: CPU: 0 PID: 30697 at fs/namespace.c:1186 mntput_no_expire+0xade/0xcc0 fs/namespace.c:1186
Modules linked in:
CPU: 0 PID: 30697 Comm: syz-executor.0 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 77 24 07 0c 01 e8 38 66 0f 07 e9 3f fd ff ff e8 32 33 a6 ff <0f> 0b e9 fc fc ff ff e8 26 33 a6 ff e8 71 10 92 ff 31 ff 89 c5 89
RSP: 0018:ffffc90001ddfc18 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 1ffff920003bbf89 RCX: 0000000000000000
RDX: ffff888025e73880 RSI: ffffffff81cf514e RDI: 0000000000000003
RBP: ffff888061a1de00 R08: 0000000000000000 R09: ffffffff904958af
R10: ffffffff81cf4e48 R11: 0000000000000000 R12: 0000000000000008
R13: ffffc90001ddfc68 R14: 00000000ffffffff R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffef72cee68 CR3: 00000000228f3000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
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
 free_nsproxy+0x43/0x4c0 kernel/nsproxy.c:191
 put_nsproxy include/linux/nsproxy.h:105 [inline]
 switch_task_namespaces+0xaf/0xd0 kernel/nsproxy.c:249
 do_exit+0xbcf/0x2a50 kernel/exit.c:824
 do_group_exit+0x125/0x310 kernel/exit.c:922
 __do_sys_exit_group kernel/exit.c:933 [inline]
 __se_sys_exit_group kernel/exit.c:931 [inline]
 __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:931
 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: Unable to access opcode bytes at RIP 0x4665af.
RSP: 002b:00007ffefc1a5d48 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007ffefc1a5f00 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000043
RBP: 0000000000000000 R08: 0000000000000025 R09: 00007ffefc1a5f00
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004bfc8a
R13: 000000000000001c R14: 00000000ffffffff R15: 00007ffefc1a5f40