syzbot

Unable to handle kernel paging request at virtual address dfff800000000068
KASAN: null-ptr-deref in range [0x0000000000000340-0x0000000000000347]
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
[dfff800000000068] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 11341 Comm: syz.4.2189 Not tainted 6.1.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __in6_dev_get include/net/addrconf.h:323 [inline]
pc : ip6_ignore_linkdown include/net/addrconf.h:414 [inline]
pc : find_match+0xa0/0xb0c net/ipv6/route.c:784
lr : find_match+0x74/0xb0c net/ipv6/route.c:781
sp : ffff800021526020
x29: ffff800021526040 x28: 1fffe0001a40bb04 x27: dfff800000000000
x26: 0000000000000340 x25: ffff0000d205d837 x24: 0000000000000201
x23: 0000000000000002 x22: ffff0000d205d820 x21: 0000000000000000
x20: 1fffe0001a40bb06 x19: 0000000000000000 x18: 0000000000000000
x17: 000000000040004e x16: ffff8000082d0750 x15: 0000000000000002
x14: 000000000000c0fe x13: 1ffff00002a0e0b1 x12: 0000000000ff0100
x11: ff0080001077fb04 x10: 0000000000000002 x9 : ffff0000dc9d1bc0
x8 : 0000000000000068 x7 : ffff8000215263d0 x6 : 0000000000000002
x5 : ffff8000215263d0 x4 : ffff8000215263c0 x3 : 0000000000000002
x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
 __in6_dev_get include/net/addrconf.h:323 [inline]
 ip6_ignore_linkdown include/net/addrconf.h:414 [inline]
 find_match+0xa0/0xb0c net/ipv6/route.c:784
 rt6_nh_find_match+0xcc/0x138 net/ipv6/route.c:824
 nexthop_for_each_fib6_nh+0x1a8/0x3d0 net/ipv4/nexthop.c:1243
 __find_rr_leaf+0x3b8/0x5c8 net/ipv6/route.c:865
 find_rr_leaf net/ipv6/route.c:893 [inline]
 rt6_select net/ipv6/route.c:937 [inline]
 fib6_table_lookup+0x308/0x8b8 net/ipv6/route.c:2223
 ip6_pol_route+0x1f4/0x1024 net/ipv6/route.c:2259
 ip6_pol_route_output+0x60/0x94 net/ipv6/route.c:2634
 pol_lookup_func include/net/ip6_fib.h:579 [inline]
 fib6_rule_lookup+0x258/0x4a8 net/ipv6/fib6_rules.c:121
 ip6_route_output_flags_noref+0x250/0x314 net/ipv6/route.c:2666
 ip6_route_output_flags+0xe4/0x368 net/ipv6/route.c:2679
 ip6_dst_lookup_tail+0x274/0x12c0 net/ipv6/ip6_output.c:1152
 ip6_dst_lookup_flow+0x54/0xe0 net/ipv6/ip6_output.c:1255
 inet6_csk_route_req+0x418/0x60c net/ipv6/inet6_connection_sock.c:51
 tcp_v6_route_req+0x2a8/0x3dc net/ipv6/tcp_ipv6.c:817
 tcp_conn_request+0xa48/0x247c net/ipv4/tcp_input.c:7068
 tcp_v6_conn_request+0x264/0x380 net/ipv6/tcp_ipv6.c:1177
 tcp_rcv_state_process+0x11d4/0x380c net/ipv4/tcp_input.c:6575
 tcp_v6_do_rcv+0x868/0x1128 net/ipv6/tcp_ipv6.c:1510
 tcp_v6_rcv+0x1978/0x1fa0 net/ipv6/tcp_ipv6.c:1739
 ip6_protocol_deliver_rcu+0x928/0x11d0 net/ipv6/ip6_input.c:438
 ip6_input_finish+0x164/0x298 net/ipv6/ip6_input.c:483
 NF_HOOK+0x2c4/0x358 include/linux/netfilter.h:302
 ip6_input+0x90/0xa8 net/ipv6/ip6_input.c:492
 dst_input include/net/dst.h:463 [inline]
 ip6_rcv_finish+0x1f4/0x220 net/ipv6/ip6_input.c:79
 NF_HOOK+0x2c4/0x358 include/linux/netfilter.h:302
 ipv6_rcv+0x9c/0xbc net/ipv6/ip6_input.c:310
 __netif_receive_skb_one_core net/core/dev.c:5569 [inline]
 __netif_receive_skb+0xcc/0x2ac net/core/dev.c:5683
 netif_receive_skb_internal net/core/dev.c:5769 [inline]
 netif_receive_skb+0x1e8/0x8f0 net/core/dev.c:5828
 tun_rx_batched+0x478/0x5b4 drivers/net/tun.c:-1
 tun_get_user+0x1fa0/0x3240 drivers/net/tun.c:1998
 tun_chr_write_iter+0xfc/0x204 drivers/net/tun.c:2044
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x5ac/0x7c4 fs/read_write.c:584
 ksys_write+0x120/0x210 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:646
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
Code: 96055809 f94002c8 910d011a d343ff48 (387b6908) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	96055809 	bl	0xfffffffff8156024
   4:	f94002c8 	ldr	x8, [x22]
   8:	910d011a 	add	x26, x8, #0x340
   c:	d343ff48 	lsr	x8, x26, #3
* 10:	387b6908 	ldrb	w8, [x8, x27] <-- trapping instruction