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BUG: KASAN: global-out-of-bounds in fib6_add_rt2node net/ipv6/ip6_fib.c:1102 [inline]
BUG: KASAN: global-out-of-bounds in fib6_add+0x3ced/0x4b60 net/ipv6/ip6_fib.c:1488
Read of size 4 at addr ffffffff9af9f590 by task kworker/u32:27/10870

CPU: 0 UID: 0 PID: 10870 Comm: kworker/u32:27 Not tainted 6.15.0-rc7-syzkaller-00099-g94305e83eccb #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
Workqueue: events_unbound linkwatch_event
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+0xc3/0x670 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 fib6_add_rt2node net/ipv6/ip6_fib.c:1102 [inline]
 fib6_add+0x3ced/0x4b60 net/ipv6/ip6_fib.c:1488
 __ip6_ins_rt net/ipv6/route.c:1351 [inline]
 ip6_route_add+0x8d/0x1c0 net/ipv6/route.c:3900
 addrconf_prefix_route+0x2fd/0x510 net/ipv6/addrconf.c:2487
 addrconf_add_linklocal+0x329/0x500 net/ipv6/addrconf.c:3312
 addrconf_addr_gen+0x36d/0x3c0 net/ipv6/addrconf.c:3441
 addrconf_dev_config net/ipv6/addrconf.c:3487 [inline]
 addrconf_init_auto_addrs+0x4b9/0x8f0 net/ipv6/addrconf.c:3571
 addrconf_notify+0x6e2/0x19e0 net/ipv6/addrconf.c:3744
 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176
 netif_state_change+0x165/0x3b0 net/core/dev.c:1530
 linkwatch_do_dev+0x12b/0x160 net/core/link_watch.c:186
 __linkwatch_run_queue+0x2aa/0x8a0 net/core/link_watch.c:244
 linkwatch_event+0x8f/0xc0 net/core/link_watch.c:304
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

The buggy address belongs to the variable:
 __key.0+0x10/0x40

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1af9f
flags: 0xfff00000002000(reserved|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002000 ffffea00006be7c8 ffffea00006be7c8 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:
 ffffffff9af9f480: 00 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9
 ffffffff9af9f500: 00 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9
>ffffffff9af9f580: 00 00 f9 f9 f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9
                         ^
 ffffffff9af9f600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f9
 ffffffff9af9f680: f9 f9 f9 f9 00 00 f9 f9 f9 f9 f9 f9 00 00 f9 f9
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