[syzbot] [net?] BUG: unable to handle kernel paging request in tcf_idrinfo_destroy

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 05c93f3395ed Merge branch 'for-next/core' into for-kernelci
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=16789eb4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=3b5338ad1e59a06c
dashboard link: https://syzkaller.appspot.com/bug?extid=8f1c492ffa4644ff3826
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6b5c913e373c/disk-05c93f33.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/15e75f1266ef/vmlinux-05c93f33.xz
kernel image: https://storage.googleapis.com/syzbot-assets/dd930129c578/Image-05c93f33.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8f1c49...@syzkaller.appspotmail.com

Unable to handle kernel paging request at virtual address dfff80000000001c
KASAN: null-ptr-deref in range [0x00000000000000e0-0x00000000000000e7]
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
[dfff80000000001c] address between user and kernel address ranges
Internal error: Oops: 0000000096000005 [#1] SMP
Modules linked in:
CPU: 1 UID: 0 PID: 252 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
Workqueue: netns cleanup_net
pstate: 63400005 (nZCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : tc_act_in_hw include/net/pkt_cls.h:288 [inline]
pc : tcf_idrinfo_destroy+0xac/0x280 net/sched/act_api.c:943
lr : tcf_idrinfo_destroy+0x9c/0x280 net/sched/act_api.c:942
sp : ffff80009bc477e0
x29: ffff80009bc47850 x28: 0000000000000001 x27: 1ffff0001251a7a6
x26: 0000000000000000 x25: ffff80009bc477e0 x24: 1ffff00013788efc
x23: dfff800000000000 x22: 00000000000000e0 x21: fffffffffffffff0
x20: ffff8000928d3d30 x19: ffff0000d7040000 x18: 00000000ffffffff
x17: ffff8000894c2344 x16: ffff80008ad6b188 x15: 0000000000000002
x14: 1ffff00013788ee6 x13: 0000000000000000 x12: 0000000000000000
x11: ffff700013788ee8 x10: 0000000000000000 x9 : 2310c4dc04add800
x8 : 000000000000001c x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000010
x2 : 0000000000000000 x1 : 0000000000000000 x0 : fffffffffffffff0
Call trace:
tc_act_in_hw include/net/pkt_cls.h:288 [inline] (P)
tcf_idrinfo_destroy+0xac/0x280 net/sched/act_api.c:943 (P)
tc_action_net_exit include/net/act_api.h:183 [inline]
gact_exit_net+0x9c/0x104 net/sched/act_gact.c:310
ops_exit_list net/core/net_namespace.c:205 [inline]
ops_undo_list+0x428/0x7ec net/core/net_namespace.c:252
cleanup_net+0x3f8/0x6dc net/core/net_namespace.c:695
process_one_work+0x7e8/0x155c kernel/workqueue.c:3263
process_scheduled_works kernel/workqueue.c:3346 [inline]
worker_thread+0x958/0xed8 kernel/workqueue.c:3427
kthread+0x5fc/0x75c kernel/kthread.c:463
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844
Code: b4000b40 9103c016 aa0003f5 d343fec8 (38f76908)
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
0: b4000b40 cbz x0, 0x168
4: 9103c016 add x22, x0, #0xf0
8: aa0003f5 mov x21, x0
c: d343fec8 lsr x8, x22, #3
* 10: 38f76908 ldrsb w8, [x8, x23] <-- trapping instruction


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