------------[ cut here ]------------
WARNING: CPU: 1 PID: 20318 at fs/namespace.c:1186 mntput_no_expire+0xada/0xcd0 fs/namespace.c:1186
Modules linked in:
CPU: 1 PID: 20318 Comm: syz-executor.3 Not tainted 5.14.0-rc5-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:1186
Code: 30 84 c0 0f 84 b9 fe ff ff 3c 03 0f 8f b1 fe ff ff 4c 89 44 24 10 e8 15 fa eb ff 4c 8b 44 24 10 e9 9d fe ff ff e8 36 56 a5 ff <0f> 0b e9 19 fd ff ff e8 2a 56 a5 ff e8 65 82 5d 07 31 ff 89 c5 89
RSP: 0018:ffffc9000176fc20 EFLAGS: 00010212
RAX: 000000000000eb3f RBX: 1ffff920002edf8a RCX: ffffc900105f4000
RDX: 0000000000040000 RSI: ffffffff81d0537a RDI: 0000000000000003
RBP: ffff88802f7a1800 R08: 0000000000000000 R09: ffffffff8fcf28ef
R10: ffffffff81d05091 R11: 0000000000000000 R12: 0000000000000008
R13: ffffc9000176fc70 R14: 00000000ffffffff R15: 0000000000000002
FS:  00007f081d2c8700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000568000 CR3: 0000000041e32000 CR4: 00000000001506e0
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
 unlock_mount fs/namespace.c:2277 [inline]
 do_loopback fs/namespace.c:2412 [inline]
 path_mount+0xcd1/0x1fa0 fs/namespace.c:3243
 do_mount fs/namespace.c:3262 [inline]
 __do_sys_mount fs/namespace.c:3470 [inline]
 __se_sys_mount fs/namespace.c:3447 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3447
 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: 0033:0x4665f9
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:00007f081d2c8188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 000000000056c0f0 RCX: 00000000004665f9
RDX: 0000000000000000 RSI: 00000000200003c0 RDI: 0000000020000000
RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000002001001 R11: 0000000000000246 R12: 000000000056c0f0
R13: 00007fff4c55282f R14: 00007f081d2c8300 R15: 0000000000022000