INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 0 PID: 4811 Comm: nfsd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/23/2026
Call trace:
 dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106
 dump_stack+0x1c/0x5c lib/dump_stack.c:113
 assign_lock_key+0x230/0x264 kernel/locking/lockdep.c:1004
 register_lock_class+0x1ac/0x698 kernel/locking/lockdep.c:1317
 __lock_acquire+0x258/0x7280 kernel/locking/lockdep.c:5048
 lock_acquire+0x210/0x63c kernel/locking/lockdep.c:5790
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x54/0x6c kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 nfsd4_exchange_id+0x518/0x1038 fs/nfsd/nfs4state.c:3446
 nfsd4_proc_compound+0x11fc/0x1f90 fs/nfsd/nfs4proc.c:2695
 nfsd_dispatch+0x4dc/0xbcc fs/nfsd/nfssvc.c:1022
 svc_process_common+0xe54/0x15c4 net/sunrpc/svc.c:1371
 svc_process+0x258/0x35c net/sunrpc/svc.c:1501
 nfsd+0x1dc/0x328 fs/nfsd/nfssvc.c:959
 kthread+0x254/0x2e0 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850
Unable to handle kernel paging request at virtual address dfff800000000016
KASAN: null-ptr-deref in range [0x00000000000000b0-0x00000000000000b7]
Mem abort info:
  ESR = 0x0000000096000006
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x06: level 2 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000006
  CM = 0, WnR = 0
[dfff800000000016] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 4811 Comm: nfsd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/23/2026
pstate: 02400005 (nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : list_add include/linux/list.h:95 [inline]
pc : add_to_unconfirmed+0x2d4/0x454 fs/nfsd/nfs4state.c:3102
lr : add_clp_to_name_tree fs/nfsd/nfs4state.c:3068 [inline]
lr : add_to_unconfirmed+0x298/0x454 fs/nfsd/nfs4state.c:3100
sp : ffff800022d67980
x29: ffff800022d67980 x28: 0000000000000000 x27: ffff0000d1a384a8
x26: 0000000000000000 x25: dfff800000000000 x24: 0000000000000000
x23: 0000000000000016 x22: ffff0000d1a38010 x21: 000000000000000b
x20: 00000000000000b0 x19: ffff0000d1a38000 x18: 1fffe00033e62d7e
x17: 0000000000000000 x16: ffff800011bc8ec8 x15: 0000000000000000
x14: 0000000000000002 x13: 1fffe0001a347003 x12: 0000000000000000
x11: 0000000000000000 x10: ffff60001a347005 x9 : 00000000be13e1cb
x8 : 0000000000000000 x7 : 0000000000000000 x6 : ffff800009295ccc
x5 : 0000000000000000 x4 : 0000000000000008 x3 : 0000000000000000
x2 : 0000000000000008 x1 : ffff0000d93f0080 x0 : ffff0000d1a38010
Call trace:
 list_add include/linux/list.h:95 [inline]
 add_to_unconfirmed+0x2d4/0x454 fs/nfsd/nfs4state.c:3102
 nfsd4_exchange_id+0x7c0/0x1038 fs/nfsd/nfs4state.c:3516
 nfsd4_proc_compound+0x11fc/0x1f90 fs/nfsd/nfs4proc.c:2695
 nfsd_dispatch+0x4dc/0xbcc fs/nfsd/nfssvc.c:1022
 svc_process_common+0xe54/0x15c4 net/sunrpc/svc.c:1371
 svc_process+0x258/0x35c net/sunrpc/svc.c:1501
 nfsd+0x1dc/0x328 fs/nfsd/nfssvc.c:959
 kthread+0x254/0x2e0 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850
Code: 97da1b78 f9400288 8b151114 d343fe97 (38796ae8) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	97da1b78 	bl	0xffffffffff686de0
   4:	f9400288 	ldr	x8, [x20]
   8:	8b151114 	add	x20, x8, x21, lsl #4
   c:	d343fe97 	lsr	x23, x20, #3
* 10:	38796ae8 	ldrb	w8, [x23, x25] <-- trapping instruction