[linux-next:master] [ns] 3a18f80918: WARNING:at_include/linux/ns_common.h:#put_cred_rcu

kernel test robot oliver.sang at intel.com
Tue Nov 11 07:08:10 UTC 2025



Hello,

kernel test robot noticed "WARNING:at_include/linux/ns_common.h:#put_cred_rcu" on:

commit: 3a18f809184bc5a1cfad7cde5b8b026e2ff61587 ("ns: add active reference count")
https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master

in testcase: trinity
version: 
with following parameters:

	runtime: 300s
	group: group-01
	nr_groups: 5



config: x86_64-randconfig-r053-20251109
compiler: gcc-14
test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 32G

(please refer to attached dmesg/kmsg for entire log/backtrace)



If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <oliver.sang at intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202511111547.de480df9-lkp@intel.com


[   41.172047][    C1] ------------[ cut here ]------------
[   41.172821][    C1] WARNING: CPU: 1 PID: 0 at include/linux/ns_common.h:227 put_cred_rcu (include/linux/ns_common.h:227 include/linux/user_namespace.h:189 kernel/cred.c:88)
[   41.173907][    C1] Modules linked in: serio_raw(F) floppy(F) tiny_power_button(F) button(F)
[   41.174959][    C1] CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: GF               T   6.18.0-rc2-00014-g3a18f809184b #1 PREEMPTLAZY  9f2dc8152166a7dcc87d7d6a6b2b12a17475cded
[   41.176815][    C1] Tainted: [F]=FORCED_MODULE, [T]=RANDSTRUCT
[   41.177517][    C1] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[   41.178764][    C1] RIP: 0010:put_cred_rcu (include/linux/ns_common.h:227 include/linux/user_namespace.h:189 kernel/cred.c:88)
[   41.179419][    C1] Code: 02 48 89 e8 83 e0 07 83 c0 03 38 d0 7c 0c 84 d2 74 08 48 89 ef e8 0d 9f 55 00 8b 83 30 03 00 00 85 c0 74 09 e8 ae 24 1c 00 90 <0f> 0b 90 e8 a5 24 1c 00 48 89 df e8 fd a9 1b 00 e8 98 24 1c 00 4c
All code
========
   0:	02 48 89             	add    -0x77(%rax),%cl
   3:	e8 83 e0 07 83       	call   0xffffffff8307e08b
   8:	c0 03 38             	rolb   $0x38,(%rbx)
   b:	d0 7c 0c 84          	sarb   $1,-0x7c(%rsp,%rcx,1)
   f:	d2 74 08 48          	shlb   %cl,0x48(%rax,%rcx,1)
  13:	89 ef                	mov    %ebp,%edi
  15:	e8 0d 9f 55 00       	call   0x559f27
  1a:	8b 83 30 03 00 00    	mov    0x330(%rbx),%eax
  20:	85 c0                	test   %eax,%eax
  22:	74 09                	je     0x2d
  24:	e8 ae 24 1c 00       	call   0x1c24d7
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	e8 a5 24 1c 00       	call   0x1c24d7
  32:	48 89 df             	mov    %rbx,%rdi
  35:	e8 fd a9 1b 00       	call   0x1baa37
  3a:	e8 98 24 1c 00       	call   0x1c24d7
  3f:	4c                   	rex.WR

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	e8 a5 24 1c 00       	call   0x1c24ad
   8:	48 89 df             	mov    %rbx,%rdi
   b:	e8 fd a9 1b 00       	call   0x1baa0d
  10:	e8 98 24 1c 00       	call   0x1c24ad
  15:	4c                   	rex.WR
[   41.181507][    C1] RSP: 0018:ffffc900001c8e58 EFLAGS: 00010246
[   41.182352][    C1] RAX: 0000000000000000 RBX: ffff8881649b8780 RCX: 0000000000000000
[   41.183326][    C1] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[   41.184311][    C1] RBP: ffff8881649b8ab0 R08: 0000000000000000 R09: 0000000000000000
[   41.185324][    C1] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88815d490c80
[   41.186287][    C1] R13: ffffffff83d2b7c0 R14: 0000000000000004 R15: ffffffff813e6e70
[   41.187244][    C1] FS:  0000000000000000(0000) GS:ffff888799e76000(0000) knlGS:0000000000000000
[   41.188285][    C1] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   41.191457][    C1] CR2: 00000000004003c0 CR3: 0000000003c88000 CR4: 00000000000406b0
[   41.192491][    C1] Call Trace:
[   41.192939][    C1]  <IRQ>
[   41.193359][    C1]  rcu_do_batch (include/linux/rcupdate.h:341 kernel/rcu/tree.c:2607)
[   41.193952][    C1]  ? rcu_pending (kernel/rcu/tree.c:2529)
[   41.194567][    C1]  ? rcu_disable_urgency_upon_qs (kernel/rcu/tree.c:725 (discriminator 1))
[   41.195408][    C1]  ? trace_irq_enable+0xac/0xe0
[   41.196177][    C1]  rcu_core (kernel/rcu/tree.c:2863)
[   41.196782][    C1]  handle_softirqs (arch/x86/include/asm/jump_label.h:36 include/trace/events/irq.h:142 kernel/softirq.c:623)
[   41.197442][    C1]  __irq_exit_rcu (kernel/softirq.c:496 kernel/softirq.c:723)
[   41.198071][    C1]  irq_exit_rcu (kernel/softirq.c:741 (discriminator 38))
[   41.198779][    C1]  sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1052 (discriminator 35) arch/x86/kernel/apic/apic.c:1052 (discriminator 35))
[   41.199466][    C1]  </IRQ>
[   41.199885][    C1]  <TASK>
[   41.200311][    C1]  asm_sysvec_apic_timer_interrupt (arch/x86/include/asm/idtentry.h:569)
[   41.201027][    C1] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:82)
[   41.201736][    C1] Code: 48 8b 3d 28 51 54 02 e8 23 00 00 00 48 2b 05 fc cf af 00 31 ff c3 cc cc cc cc cc cc cc cc cc eb 07 0f 00 2d 97 fc 0e 00 fb f4 <c3> cc cc cc cc 41 57 41 56 41 55 41 54 55 48 89 fd 53 44 8b 6d 00
All code
========
   0:	48 8b 3d 28 51 54 02 	mov    0x2545128(%rip),%rdi        # 0x254512f
   7:	e8 23 00 00 00       	call   0x2f
   c:	48 2b 05 fc cf af 00 	sub    0xafcffc(%rip),%rax        # 0xafd00f
  13:	31 ff                	xor    %edi,%edi
  15:	c3                   	ret
  16:	cc                   	int3
  17:	cc                   	int3
  18:	cc                   	int3
  19:	cc                   	int3
  1a:	cc                   	int3
  1b:	cc                   	int3
  1c:	cc                   	int3
  1d:	cc                   	int3
  1e:	cc                   	int3
  1f:	eb 07                	jmp    0x28
  21:	0f 00 2d 97 fc 0e 00 	verw   0xefc97(%rip)        # 0xefcbf
  28:	fb                   	sti
  29:	f4                   	hlt
  2a:*	c3                   	ret		<-- trapping instruction
  2b:	cc                   	int3
  2c:	cc                   	int3
  2d:	cc                   	int3
  2e:	cc                   	int3
  2f:	41 57                	push   %r15
  31:	41 56                	push   %r14
  33:	41 55                	push   %r13
  35:	41 54                	push   %r12
  37:	55                   	push   %rbp
  38:	48 89 fd             	mov    %rdi,%rbp
  3b:	53                   	push   %rbx
  3c:	44 8b 6d 00          	mov    0x0(%rbp),%r13d

Code starting with the faulting instruction
===========================================
   0:	c3                   	ret
   1:	cc                   	int3
   2:	cc                   	int3
   3:	cc                   	int3
   4:	cc                   	int3
   5:	41 57                	push   %r15
   7:	41 56                	push   %r14
   9:	41 55                	push   %r13
   b:	41 54                	push   %r12
   d:	55                   	push   %rbp
   e:	48 89 fd             	mov    %rdi,%rbp
  11:	53                   	push   %rbx
  12:	44 8b 6d 00          	mov    0x0(%rbp),%r13d
[   41.203822][    C1] RSP: 0018:ffffc9000014fe38 EFLAGS: 00000246
[   41.204551][    C1] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[   41.205618][    C1] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[   41.206601][    C1] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[   41.207613][    C1] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881008322c0
[   41.208650][    C1] R13: 1ffff92000029fca R14: dffffc0000000000 R15: 0000000000000000
[   41.209689][    C1]  default_idle (arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:767)
[   41.210257][    C1]  default_idle_call (include/linux/cpuidle.h:143 (discriminator 1) kernel/sched/idle.c:123 (discriminator 1))
[   41.210879][    C1]  cpuidle_idle_call (kernel/sched/idle.c:191)
[   41.211506][    C1]  ? arch_cpu_idle_exit+0x30/0x30
[   41.215390][    C1]  ? tick_nohz_start_idle (kernel/time/tick-sched.c:753)
[   41.216069][    C1]  ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:81)
[   41.216763][    C1]  do_idle (kernel/sched/idle.c:332)
[   41.217295][    C1]  cpu_startup_entry (kernel/sched/idle.c:427)
[   41.217929][    C1]  start_secondary (arch/x86/kernel/smpboot.c:315)
[   41.218650][    C1]  ? set_cpu_sibling_map (arch/x86/kernel/smpboot.c:233)
[   41.219100][    C1]  common_startup_64 (arch/x86/kernel/head_64.S:419)
[   41.219506][    C1]  </TASK>
[   41.219783][    C1] irq event stamp: 42022
[   41.220131][    C1] hardirqs last  enabled at (42021): tick_nohz_idle_exit (arch/x86/include/asm/irqflags.h:42 arch/x86/include/asm/irqflags.h:119 kernel/time/tick-sched.c:1472)
[   41.220844][    C1] hardirqs last disabled at (42022): __schedule (kernel/sched/core.c:6814)
[   41.221520][    C1] softirqs last  enabled at (42010): handle_softirqs (kernel/softirq.c:469 (discriminator 2) kernel/softirq.c:650 (discriminator 2))
[   41.222380][    C1] softirqs last disabled at (42001): __irq_exit_rcu (kernel/softirq.c:496 kernel/softirq.c:723)
[   41.223139][    C1] ---[ end trace 0000000000000000 ]---


The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20251111/202511111547.de480df9-lkp@intel.com



-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki




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