Oops: general protection fault, probably for non-canonical address 0xdffffc0000000031: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000188-0x000000000000018f]
CPU: 0 PID: 111 Comm: kswapd0 Not tainted 6.9.0-syzkaller-11919-g5f16eb0549ab #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:check_init_srcu_struct+0x44/0x170 kernel/rcu/srcutree.c:408
Code: 53 48 89 fb 80 3c 02 00 0f 85 fe 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 38 48 8d bd 88 01 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 ce 00 00 00 48 8b 85 88 01 00 00 a8 03 75 0b 5b
RSP: 0018:ffffc90000dff578 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff888061d842c0 RCX: ffffffff83eef098
RDX: 0000000000000031 RSI: 0000000000000000 RDI: 0000000000000188
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000006 R12: ffff888061d842f8
R13: ffff888020a7b3a0 R14: 0000000000000001 R15: ffff888061d80000
FS:  0000000000000000(0000) GS:ffff88802c000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561b26225668 CR3: 000000004a0ba000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 srcu_gp_start_if_needed+0x80/0xf00 kernel/rcu/srcutree.c:1221
 bkey_cached_free fs/bcachefs/btree_key_cache.c:90 [inline]
 bch2_btree_key_cache_scan+0xb90/0x1820 fs/bcachefs/btree_key_cache.c:886
 do_shrink_slab+0x44f/0x11c0 mm/shrinker.c:435
 shrink_slab+0x18a/0x1310 mm/shrinker.c:662
 shrink_one+0x493/0x7c0 mm/vmscan.c:4790
 shrink_many mm/vmscan.c:4851 [inline]
 lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951
 shrink_node mm/vmscan.c:5910 [inline]
 kswapd_shrink_node mm/vmscan.c:6720 [inline]
 balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911
 kswapd+0x5ea/0xbf0 mm/vmscan.c:7180
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:check_init_srcu_struct+0x44/0x170 kernel/rcu/srcutree.c:408
Code: 53 48 89 fb 80 3c 02 00 0f 85 fe 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 38 48 8d bd 88 01 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 ce 00 00 00 48 8b 85 88 01 00 00 a8 03 75 0b 5b
RSP: 0018:ffffc90000dff578 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff888061d842c0 RCX: ffffffff83eef098
RDX: 0000000000000031 RSI: 0000000000000000 RDI: 0000000000000188
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000006 R12: ffff888061d842f8
R13: ffff888020a7b3a0 R14: 0000000000000001 R15: ffff888061d80000
FS:  0000000000000000(0000) GS:ffff88802c000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561b26225668 CR3: 000000004a0ba000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	53                   	push   %rbx
   1:	48 89 fb             	mov    %rdi,%rbx
   4:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   8:	0f 85 fe 00 00 00    	jne    0x10c
   e:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  15:	fc ff df
  18:	48 8b 6b 38          	mov    0x38(%rbx),%rbp
  1c:	48 8d bd 88 01 00 00 	lea    0x188(%rbp),%rdi
  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:	0f 85 ce 00 00 00    	jne    0x102
  34:	48 8b 85 88 01 00 00 	mov    0x188(%rbp),%rax
  3b:	a8 03                	test   $0x3,%al
  3d:	75 0b                	jne    0x4a
  3f:	5b                   	pop    %rbx