blkdev_ioctl+0x27c/0x6c0
 __x64_sys_ioctl+0x18f/0x210
 do_syscall_64+0xbf/0x360
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
------------[ cut here ]------------
WARNING: fs/namespace.c:1434 at mntput_no_expire+0x78e/0xbe0, CPU#0: syz-executor.5/4033
Modules linked in:
CPU: 0 UID: 0 PID: 4033 Comm: syz-executor.5 Tainted: G        W           6.17.0-rc4-next-20250901 #1 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:mntput_no_expire+0x78e/0xbe0
Code: 05 d6 30 81 04 01 e8 71 df 91 ff e9 41 fc ff ff e8 27 47 b4 ff 31 ff 44 89 ee e8 4d 42 b4 ff 45 85 ed 79 09 e8 13 47 b4 ff 90 <0f> 0b 90 e8 0a 47 b4 ff e8 b5 2d fc 02 31 ff 89 c5 89 c6 e8 2a 42
RSP: 0018:ffff88800d9579b8 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 1ffff11001b2af3c RCX: ffffffff81bfaf93
RDX: ffff88801418b700 RSI: ffffffff81bfaf9d RDI: 0000000000000005
RBP: ffff88801e83ce00 R08: 0000000000000001 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000001 R12: ffff88800d957a20
R13: 00000000ffffffff R14: dead000000000100 R15: ffff88801e83ce00
FS:  0000000000000000(0000) GS:ffff8880e55d8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffb8 CR3: 0000000037981000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 namespace_unlock+0x7f1/0x810
 put_mnt_ns+0xf5/0x120
 free_nsproxy+0x3a/0x400
 switch_task_namespaces+0xe2/0x100
 do_exit+0x841/0x2970
 do_group_exit+0xd3/0x2a0
 get_signal+0x2315/0x2340
 arch_do_signal_or_restart+0x80/0x790
 irqentry_exit_to_user_mode+0x106/0x1c0
 exc_page_fault+0xd9/0x180
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0xe
Code: Unable to access opcode bytes at 0xffffffffffffffe4.
RSP: 002b:00007fc51d518190 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fc5200d7020 RCX: 00007fc51ffc3b19
RDX: 0000000000000000 RSI: 0000000000000058 RDI: 00000000200002c0
RBP: 00007fc52001df6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe2cd35c6f R14: 00007fc51d518300 R15: 0000000000022000
 </TASK>
irq event stamp: 1227
hardirqs last  enabled at (1235): [<ffffffff81541b18>] __up_console_sem+0x78/0x80
hardirqs last disabled at (1244): [<ffffffff81541afd>] __up_console_sem+0x5d/0x80
softirqs last  enabled at (854): [<ffffffff813bafcc>] handle_softirqs+0x50c/0x770
softirqs last disabled at (583): [<ffffffff813bb364>] __irq_exit_rcu+0xc4/0x100
---[ end trace 0000000000000000 ]---
kmemleak: Automatic memory scanning thread ended
EXT4-fs (loop0): mounted filesystem 76b65be2-f6da-4727-8c75-0525a5b65a09 r/w without journal. Quota mode: none.
ext4 filesystem being mounted at /syzkaller-testdir069299242/syzkaller.R19EvQ/3/mnt supports timestamps until 2038-01-19 (0x7fffffff)
EXT4-fs (loop0): unmounting filesystem 76b65be2-f6da-4727-8c75-0525a5b65a09.
audit: type=1326 audit(1756752630.959:20): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=3987 comm="syz-executor.7" exe="/syz-executor.7" sig=31 arch=c000003e syscall=202 compat=0 ip=0x7f5610d5fb19 code=0x0