[syzbot] [arm?] BUG: unable to handle kernel paging request in trans_pgd_create_copy

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    2c71fdf02a95 Merge tag 'drm-fixes-2024-04-09' of https://g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13400033180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=3b59c588989b5f9a
dashboard link: https://syzkaller.appspot.com/bug?extid=2d1f5a94167d430a3bd7
compiler:       aarch64-linux-gnu-gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17a303d3180000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=128de44d180000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/384ffdcca292/non_bootable_disk-2c71fdf0.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/627c4a5b3fcb/vmlinux-2c71fdf0.xz
kernel image: https://storage.googleapis.com/syzbot-assets/39628cd13511/Image-2c71fdf0.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2d1f5a94167d430a3bd7@xxxxxxxxxxxxxxxxxxxxxxxxx

Unable to handle kernel paging request at virtual address ffffffffc0000000
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, ISS2 = 0x00000000
  CM = 0, WnR = 0, TnD = 0, TagAccess = 0
  GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
swapper pgtable: 4k pages, 52-bit VAs, pgdp=00000000425f4000
[ffffffffc0000000] pgd=1000000042ac9003, p4d=00000000429e0003, pud=00000000429e1003, pmd=0000000000000000
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 3174 Comm: syz-executor195 Not tainted 6.9.0-rc3-syzkaller-00023-g2c71fdf02a95 #0
Hardware name: linux,dummy-virt (DT)
pstate: 81400009 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
pc : copy_pud arch/arm64/mm/trans_pgd.c:127 [inline]
pc : copy_p4d arch/arm64/mm/trans_pgd.c:169 [inline]
pc : copy_page_tables arch/arm64/mm/trans_pgd.c:188 [inline]
pc : trans_pgd_create_copy+0x164/0x864 arch/arm64/mm/trans_pgd.c:215
lr : trans_alloc arch/arm64/mm/trans_pgd.c:31 [inline]
lr : trans_pgd_create_copy+0x2c/0x864 arch/arm64/mm/trans_pgd.c:208
sp : ffff8000893b3c30
x29: ffff8000893b3c30 x28: f9f00000058e9200 x27: fff0000000000000
x26: fff1000000000000 x25: fff0008000000000 x24: fff0000000000000
x23: ffff800000000000 x22: ffffffffc0000000 x21: fff000007fdff000
x20: ffff8000893b3d68 x19: ffffffffc0000000 x18: 0000000000000001
x17: ffff800080171268 x16: ffff800080170f48 x15: ffff80008016f800
x14: 0000000000000002 x13: 0000000000000000 x12: 0000000000072170
x11: 000000000003cd0d x10: 0000000000000001 x9 : 0000000000000000
x8 : f1f0000007ef9000 x7 : 0000000000000000 x6 : 000000000000003f
x5 : 0000000000000040 x4 : 0000000000000000 x3 : 1000000000000000
x2 : 00000000bfdff000 x1 : fff0ffffffffffff x0 : 18000000bfdfe003
Call trace:
 copy_p4d arch/arm64/mm/trans_pgd.c:167 [inline]
 copy_page_tables arch/arm64/mm/trans_pgd.c:188 [inline]
 trans_pgd_create_copy+0x164/0x864 arch/arm64/mm/trans_pgd.c:215
 machine_kexec_post_load+0xa4/0x2c0 arch/arm64/kernel/machine_kexec.c:135
 do_kexec_load+0x28c/0x2e4 kernel/kexec.c:162
 __do_sys_kexec_load kernel/kexec.c:261 [inline]
 __se_sys_kexec_load kernel/kexec.c:242 [inline]
 __arm64_sys_kexec_load+0x9c/0xe8 kernel/kexec.c:242
 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline]
 invoke_syscall+0x48/0x114 arch/arm64/kernel/syscall.c:48
 el0_svc_common.constprop.0+0x40/0xe0 arch/arm64/kernel/syscall.c:133
 do_el0_svc+0x1c/0x28 arch/arm64/kernel/syscall.c:152
 el0_svc+0x34/0xf8 arch/arm64/kernel/entry-common.c:712
 el0t_64_sync_handler+0x100/0x12c arch/arm64/kernel/entry-common.c:730
 el0t_64_sync+0x19c/0x1a0 arch/arm64/kernel/entry.S:598
Code: eb01001f f94002a0 54fff9a2 b4002380 (f94002c0) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	eb01001f 	cmp	x0, x1
   4:	f94002a0 	ldr	x0, [x21]
   8:	54fff9a2 	b.cs	0xffffffffffffff3c  // b.hs, b.nlast
   c:	b4002380 	cbz	x0, 0x47c
* 10:	f94002c0 	ldr	x0, [x22] <-- trapping instruction


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