Oops: general protection fault, probably for non-canonical address 0xdffffc0000000017: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x00000000000000b8-0x00000000000000bf]
CPU: 1 UID: 0 PID: 5657 Comm: syz-executor.3 Not tainted 6.18.0-rc5-next-20251114 #1 PREEMPT(voluntary) 
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:put_pid_ns+0x30/0x80
Code: 89 fd 53 e8 42 a0 03 00 48 85 ed 74 3d e8 38 a0 03 00 48 8d bd d0 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 35 48 8b 9d d0 00 00 00 bf 08 00 00 00 48 89 de e8
RSP: 0018:ffff88801c06fdb0 EFLAGS: 00010216
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffc9000c859000
RDX: 0000000000000017 RSI: ffffffff817193a8 RDI: 00000000000000ba
RBP: ffffffffffffffea R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff8664ed57 R11: 0000000000000001 R12: ffff88801999d110
R13: ffff88801999d2c4 R14: ffffffff85cfdf20 R15: ffff88800f13bff8
FS:  00007f1401dbe700(0000) GS:ffff8880e548f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe9fbd3fc8 CR3: 000000004d62d000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 nsproxy_free+0xfa/0x5a0
 create_new_namespaces+0x585/0x750
 unshare_nsproxy_namespaces+0xc0/0x200
 ksys_unshare+0x468/0xa10
 __x64_sys_unshare+0x31/0x40
 do_syscall_64+0xbf/0x430
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1404848b19
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:00007f1401dbe188 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f140495bf60 RCX: 00007f1404848b19
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000002c020600
RBP: 00007f14048a2f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdab18e8cf R14: 00007f1401dbe300 R15: 0000000000022000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:put_pid_ns+0x30/0x80
Code: 89 fd 53 e8 42 a0 03 00 48 85 ed 74 3d e8 38 a0 03 00 48 8d bd d0 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 35 48 8b 9d d0 00 00 00 bf 08 00 00 00 48 89 de e8
RSP: 0018:ffff88801c06fdb0 EFLAGS: 00010216
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffc9000c859000
RDX: 0000000000000017 RSI: ffffffff817193a8 RDI: 00000000000000ba
RBP: ffffffffffffffea R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff8664ed57 R11: 0000000000000001 R12: ffff88801999d110
R13: ffff88801999d2c4 R14: ffffffff85cfdf20 R15: ffff88800f13bff8
FS:  00007f1401dbe700(0000) GS:ffff8880e548f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe9fbd3fc8 CR3: 000000004d62d000 CR4: 0000000000350ef0
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
CPU: 0 UID: 0 PID: 5674 Comm: syz-executor.6 Tainted: G      D             6.18.0-rc5-next-20251114 #1 PREEMPT(voluntary) 
Tainted: [D]=DIE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xfa/0x120
 should_fail_ex+0x4d7/0x5e0
 _copy_to_user+0x32/0xd0
 simple_read_from_buffer+0xe0/0x180
 proc_fail_nth_read+0x18a/0x240
 vfs_read+0x1eb/0xc70
 ksys_read+0x121/0x240
 do_syscall_64+0xbf/0x430
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f31e882c69c
Code: ec 28 48 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 fc ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 34 44 89 c7 48 89 44 24 08 e8 2f fd ff ff 48
RSP: 002b:00007f31e5def170 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f31e882c69c
RDX: 000000000000000f RSI: 00007f31e5def1e0 RDI: 0000000000000004
RBP: 00007f31e5def1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffd1e5bce9f R14: 00007f31e5def300 R15: 0000000000022000
 </TASK>
----------------
Code disassembly (best guess):
   0:	89 fd                	mov    %edi,%ebp
   2:	53                   	push   %rbx
   3:	e8 42 a0 03 00       	callq  0x3a04a
   8:	48 85 ed             	test   %rbp,%rbp
   b:	74 3d                	je     0x4a
   d:	e8 38 a0 03 00       	callq  0x3a04a
  12:	48 8d bd d0 00 00 00 	lea    0xd0(%rbp),%rdi
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	48 89 fa             	mov    %rdi,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	75 35                	jne    0x65
  30:	48 8b 9d d0 00 00 00 	mov    0xd0(%rbp),%rbx
  37:	bf 08 00 00 00       	mov    $0x8,%edi
  3c:	48 89 de             	mov    %rbx,%rsi
  3f:	e8                   	.byte 0xe8