[linux-next:master] [landlock] 9d65581539: WARNING:suspicious_RCU_usage

[kernel test robot <oliver.sang@intel.com>]

hi, Mickaël Salaün,

we just reported a random
"Oops:general_protection_fault,probably_for_non-canonical_address#:#[##]SMP_KASAN"
issue in
https://lore.kernel.org/all/202503261534.22d970e8-lkp@intel.com/

now we noticed this commit is also in linux-next/master.

we don't have enough knowledge to check the difference, but we found a
persistent issue for this commit.

6d9ac5e4d70eba3e 9d65581539252fdb1666917a095
---------------- ---------------------------
       fail:runs  %reproduction    fail:runs
           |             |             |
           :6          100%           6:6     dmesg.WARNING:suspicious_RCU_usage
           :6          100%           6:6     dmesg.boot_failures
           :6          100%           6:6     dmesg.kernel/pid.c:#suspicious_rcu_dereference_check()usage

below full report FYI.


Hello,

kernel test robot noticed "WARNING:suspicious_RCU_usage" on:

commit: 9d65581539252fdb1666917a09549c13090fe9e5 ("landlock: Always allow signals between threads of the same process")
https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master

[test failed on linux-next/master eb4bc4b07f66f01618d9cb1aa4eaef59b1188415]

in testcase: trinity
version: trinity-x86_64-ba2360ed-1_20241228
with following parameters:

	runtime: 300s
	group: group-00
	nr_groups: 5



config: x86_64-randconfig-101-20250325
compiler: gcc-12
test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G

(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@intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202503261510.f9652c11-lkp@intel.com


[  166.893101][ T3747] WARNING: suspicious RCU usage
[  166.893462][ T3747] 6.14.0-rc5-00006-g9d6558153925 #1 Not tainted
[  166.893895][ T3747] -----------------------------
[  166.894239][ T3747] kernel/pid.c:414 suspicious rcu_dereference_check() usage!
[  166.894747][ T3747]
[  166.894747][ T3747] other info that might help us debug this:
[  166.894747][ T3747]
[  166.895450][ T3747]
[  166.895450][ T3747] rcu_scheduler_active = 2, debug_locks = 1
[  166.896030][ T3747] 3 locks held by trinity-c2/3747:
[ 166.896415][ T3747] #0: ffff888114a5a930 (&group->mark_mutex){+.+.}-{4:4}, at: fcntl_dirnotify (include/linux/sched/mm.h:332 include/linux/sched/mm.h:386 include/linux/fsnotify_backend.h:279 fs/notify/dnotify/dnotify.c:329) 
[ 166.897165][ T3747] #1: ffff888148bbea60 (&mark->lock){+.+.}-{3:3}, at: fcntl_dirnotify (fs/notify/dnotify/dnotify.c:349) 
[ 166.897831][ T3747] #2: ffff888108a53220 (&f_owner->lock){....}-{3:3}, at: __f_setown (fs/fcntl.c:137) 
[  166.898481][ T3747]
[  166.898481][ T3747] stack backtrace:
[  166.898901][ T3747] CPU: 0 UID: 65534 PID: 3747 Comm: trinity-c2 Not tainted 6.14.0-rc5-00006-g9d6558153925 #1
[  166.898908][ T3747] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[  166.898912][ T3747] Call Trace:
[  166.898916][ T3747]  <TASK>
[ 166.898921][ T3747] dump_stack_lvl (lib/dump_stack.c:123) 
[ 166.898932][ T3747] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6848) 
[ 166.898945][ T3747] pid_task (kernel/pid.c:414 (discriminator 11)) 
[ 166.898954][ T3747] hook_file_set_fowner (security/landlock/fs.c:1651 (discriminator 9)) 
[ 166.898963][ T3747] security_file_set_fowner (arch/x86/include/asm/atomic.h:23 (discriminator 4) include/linux/atomic/atomic-arch-fallback.h:457 (discriminator 4) include/linux/jump_label.h:262 (discriminator 4) security/security.c:3062 (discriminator 4)) 
[ 166.898969][ T3747] __f_setown (fs/fcntl.c:145) 
[ 166.898980][ T3747] fcntl_dirnotify (fs/notify/dnotify/dnotify.c:233 fs/notify/dnotify/dnotify.c:371) 
[ 166.898996][ T3747] do_fcntl (fs/fcntl.c:539) 
[ 166.899002][ T3747] ? f_getown (fs/fcntl.c:448) 
[ 166.899007][ T3747] ? check_prev_add (kernel/locking/lockdep.c:3862) 
[ 166.899011][ T3747] ? do_syscall_64 (arch/x86/entry/common.c:102) 
[ 166.899023][ T3747] ? syscall_exit_to_user_mode (include/linux/entry-common.h:361 kernel/entry/common.c:220) 
[ 166.899038][ T3747] __x64_sys_fcntl (fs/fcntl.c:591 fs/fcntl.c:576 fs/fcntl.c:576) 
[ 166.899050][ T3747] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 166.899062][ T3747] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[ 166.899072][ T3747] ? __lock_release+0x10b/0x440 
[ 166.899076][ T3747] ? __task_pid_nr_ns (include/linux/rcupdate.h:347 include/linux/rcupdate.h:880 kernel/pid.c:514) 
[ 166.899082][ T3747] ? reacquire_held_locks (kernel/locking/lockdep.c:5502) 
[ 166.899087][ T3747] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4470) 
[ 166.899093][ T3747] ? do_syscall_64 (arch/x86/entry/common.c:102) 
[ 166.899099][ T3747] ? do_syscall_64 (arch/x86/entry/common.c:102) 
[ 166.899111][ T3747] ? syscall_exit_to_user_mode (include/linux/entry-common.h:361 kernel/entry/common.c:220) 
[ 166.899119][ T3747] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:469 kernel/locking/lockdep.c:4409) 
[ 166.899124][ T3747] ? do_syscall_64 (arch/x86/entry/common.c:102) 
[ 166.899129][ T3747] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4470) 
[ 166.899134][ T3747] ? do_syscall_64 (arch/x86/entry/common.c:102) 
[ 166.899139][ T3747] ? do_int80_emulation (arch/x86/include/asm/atomic.h:23 include/linux/atomic/atomic-arch-fallback.h:457 include/linux/jump_label.h:262 arch/x86/entry/common.c:230) 
[ 166.899149][ T3747] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[  166.899155][ T3747] RIP: 0033:0x7f55ad007719
[ 166.899159][ T3747] Code: 08 89 e8 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 90 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 8b 0d b7 06 0d 00 f7 d8 64 89 01 48
All code
========
   0:	08 89 e8 5b 5d c3    	or     %cl,-0x3ca2a418(%rcx)
   6:	66 2e 0f 1f 84 00 00 	cs nopw 0x0(%rax,%rax,1)
   d:	00 00 00 
  10:	90                   	nop
  11:	48 89 f8             	mov    %rdi,%rax
  14:	48 89 f7             	mov    %rsi,%rdi
  17:	48 89 d6             	mov    %rdx,%rsi
  1a:	48 89 ca             	mov    %rcx,%rdx
  1d:	4d 89 c2             	mov    %r8,%r10
  20:	4d 89 c8             	mov    %r9,%r8
  23:	4c 8b 4c 24 08       	mov    0x8(%rsp),%r9
  28:	0f 05                	syscall
  2a:*	48 3d 01 f0 ff ff    	cmp    $0xfffffffffffff001,%rax		<-- trapping instruction
  30:	73 01                	jae    0x33
  32:	c3                   	ret
  33:	48 8b 0d b7 06 0d 00 	mov    0xd06b7(%rip),%rcx        # 0xd06f1
  3a:	f7 d8                	neg    %eax
  3c:	64 89 01             	mov    %eax,%fs:(%rcx)
  3f:	48                   	rex.W

Code starting with the faulting instruction
===========================================
   0:	48 3d 01 f0 ff ff    	cmp    $0xfffffffffffff001,%rax
   6:	73 01                	jae    0x9
   8:	c3                   	ret
   9:	48 8b 0d b7 06 0d 00 	mov    0xd06b7(%rip),%rcx        # 0xd06c7
  10:	f7 d8                	neg    %eax
  12:	64 89 01             	mov    %eax,%fs:(%rcx)
  15:	48                   	rex.W
[  166.899164][ T3747] RSP: 002b:00007ffff6eefb48 EFLAGS: 00000246 ORIG_RAX: 0000000000000048
[  166.899168][ T3747] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f55ad007719
[  166.899172][ T3747] RDX: 0000000000000027 RSI: 0000000000000402 RDI: 0000000000000043
[  166.899174][ T3747] RBP: 00007f55ab92f058 R08: 0000000099999999 R09: 00000000377dd000
[  166.899177][ T3747] R10: 0000000084848484 R11: 0000000000000246 R12: 0000000000000048
[  166.899180][ T3747] R13: 00007f55acf036c0 R14: 00007f55ab92f058 R15: 00007f55ab92f000
[  166.899203][ T3747]  </TASK>


The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20250326/202503261510.f9652c11-lkp@intel.com



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