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BUG: KASAN: global-out-of-bounds in fib6_clean_node+0x51c/0x5b0 net/ipv6/ip6_fib.c:2251
Read of size 8 at addr ffffffff9b218588 by task syz.6.2574/14359

CPU: 1 UID: 0 PID: 14359 Comm: syz.6.2574 Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xcd/0x680 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 fib6_clean_node+0x51c/0x5b0 net/ipv6/ip6_fib.c:2251
 fib6_walk_continue+0x452/0x8d0 net/ipv6/ip6_fib.c:2177
 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2225
 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2305
 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2321
 rt6_sync_down_dev net/ipv6/route.c:5004 [inline]
 rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:5009
 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3857
 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3780
 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230
 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
 call_netdevice_notifiers net/core/dev.c:2282 [inline]
 unregister_netdevice_many_notify+0xf9a/0x26f0 net/core/dev.c:12076
 unregister_netdevice_many net/core/dev.c:12139 [inline]
 unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:11983
 unregister_netdevice include/linux/netdevice.h:3379 [inline]
 __tun_detach+0x1249/0x1540 drivers/net/tun.c:620
 tun_detach drivers/net/tun.c:636 [inline]
 tun_chr_close+0xc2/0x230 drivers/net/tun.c:3396
 __fput+0x402/0xb70 fs/file_table.c:465
 task_work_run+0x14d/0x240 kernel/task_work.c:227
 get_signal+0x1d1/0x26d0 kernel/signal.c:2807
 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f899638e969
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8993d91038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007f89965b6240 RCX: 00007f899638e969
RDX: 0000200000000000 RSI: 00000000400454ca RDI: 000000000000000a
RBP: 00007f8996410ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f89965b6240 R15: 00007ffcf9fe3768
 </TASK>

The buggy address belongs to the variable:
 binder_devices+0x8/0x40

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1b218
flags: 0xfff00000002000(reserved|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002000 ffffea00006c8608 ffffea00006c8608 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner info is not present (never set?)

Memory state around the buggy address:
 ffffffff9b218480: 00 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9
 ffffffff9b218500: 00 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9
>ffffffff9b218580: 00 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9
                      ^
 ffffffff9b218600: 00 00 f9 f9 f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9
 ffffffff9b218680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f9
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