syzbot

Unable to handle kernel paging request at virtual address dfff80001fffc000
KASAN: probably user-memory-access in range [0x00000000fffe0000-0x00000000fffe0007]
Mem abort info:
  ESR = 0x0000000096000005
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x05: level 1 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
  CM = 0, WnR = 0, TnD = 0, TagAccess = 0
  GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[dfff80001fffc000] address between user and kernel address ranges
Internal error: Oops: 0000000096000005 [#1]  SMP
Modules linked in:
CPU: 1 UID: 0 PID: 9694 Comm: dhcpcd Not tainted 6.17.0-rc1-syzkaller-g8f5ae30d69d7 #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 23400005 (nzCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : __ref_is_percpu include/linux/percpu-refcount.h:174 [inline]
pc : percpu_ref_get_many+0x80/0x1f4 include/linux/percpu-refcount.h:204
lr : rcu_read_lock include/linux/rcupdate.h:842 [inline]
lr : percpu_ref_get_many+0x3c/0x1f4 include/linux/percpu-refcount.h:202
sp : ffff8000a02475e0
x29: ffff8000a02475f0 x28: 1fffe000337a33a8 x27: dfff800000000000
x26: ffff00019bd19d40 x25: ffff00019bd19d00 x24: 0000000000000001
x23: 1fffe000337a33a6 x22: 0000000000000078 x21: dfff800000000000
x20: 00000000fffe0000 x19: 0000000000000001 x18: 0000000000000000
x17: ffff0001fea8c8b0 x16: ffff80008b007230 x15: 0000000000000001
x14: 1fffe000183390d5 x13: 0000000000000000 x12: 0000000000000000
x11: 00000000a00541d0 x10: 0000000000000003 x9 : ffff80008f7149f8
x8 : 000000001fffc000 x7 : ffff800080ce4cd0 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000002
x2 : 0000000000000008 x1 : ffff80008b6577c0 x0 : 0000000000000001
Call trace:
 __ref_is_percpu include/linux/percpu-refcount.h:174 [inline] (P)
 percpu_ref_get_many+0x80/0x1f4 include/linux/percpu-refcount.h:204 (P)
 percpu_ref_get include/linux/percpu-refcount.h:222 [inline]
 obj_cgroup_get include/linux/memcontrol.h:772 [inline]
 refill_obj_stock+0x1d0/0x574 mm/memcontrol.c:3042
 __memcg_slab_free_hook+0xd8/0x208 mm/memcontrol.c:3216
 memcg_slab_free_hook mm/slub.c:2242 [inline]
 slab_free mm/slub.c:4677 [inline]
 kmem_cache_free+0x270/0x550 mm/slub.c:4782
 anon_vma_chain_free mm/rmap.c:147 [inline]
 unlink_anon_vmas+0x224/0x520 mm/rmap.c:421
 free_pgtables+0x3c8/0x5d4 mm/memory.c:413
 exit_mmap+0x350/0xabc mm/mmap.c:1291
 __mmput+0xec/0x3f4 kernel/fork.c:1130
 mmput+0x70/0xac kernel/fork.c:1152
 exit_mm+0x13c/0x200 kernel/exit.c:582
 do_exit+0x4bc/0x1a14 kernel/exit.c:949
 do_group_exit+0x194/0x22c kernel/exit.c:1102
 __do_sys_exit_group kernel/exit.c:1113 [inline]
 __se_sys_exit_group kernel/exit.c:1111 [inline]
 pid_child_should_wake+0x0/0x1dc kernel/exit.c:1111
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
Code: 97e12a6f d343fe88 d2d00015 f2fbfff5 (38756908) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	97e12a6f 	bl	0xffffffffff84a9bc
   4:	d343fe88 	lsr	x8, x20, #3
   8:	d2d00015 	mov	x21, #0x800000000000        	// #140737488355328
   c:	f2fbfff5 	movk	x21, #0xdfff, lsl #48
* 10:	38756908 	ldrb	w8, [x8, x21] <-- trapping instruction