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BUG: KASAN: global-out-of-bounds in fib6_clean_node+0x35d/0x590 net/ipv6/ip6_fib.c:2198
Read of size 8 at addr ffffffff99d16868 by task syz.0.3224/17594

CPU: 0 UID: 0 PID: 17594 Comm: syz.0.3224 Not tainted 6.15.0-rc5-syzkaller-00353-gcd802e7e5f1e #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xb4/0x290 mm/kasan/report.c:521
 kasan_report+0x118/0x150 mm/kasan/report.c:634
 fib6_clean_node+0x35d/0x590 net/ipv6/ip6_fib.c:2198
 fib6_walk_continue+0x678/0x910 net/ipv6/ip6_fib.c:2124
 fib6_walk+0x149/0x290 net/ipv6/ip6_fib.c:2172
 fib6_clean_tree net/ipv6/ip6_fib.c:2252 [inline]
 __fib6_clean_all+0x234/0x380 net/ipv6/ip6_fib.c:2268
 rt6_sync_down_dev net/ipv6/route.c:4951 [inline]
 rt6_disable_ip+0x120/0x720 net/ipv6/route.c:4956
 addrconf_ifdown+0x15d/0x1880 net/ipv6/addrconf.c:3857
 addrconf_notify+0x1bc/0x1010 net/ipv6/addrconf.c:-1
 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline]
 call_netdevice_notifiers net/core/dev.c:2228 [inline]
 unregister_netdevice_many_notify+0x15d8/0x2330 net/core/dev.c:11970
 unregister_netdevice_many net/core/dev.c:12034 [inline]
 unregister_netdevice_queue+0x33c/0x380 net/core/dev.c:11877
 unregister_netdevice include/linux/netdevice.h:3374 [inline]
 __tun_detach+0xda4/0x1560 drivers/net/tun.c:620
 tun_detach drivers/net/tun.c:636 [inline]
 tun_chr_close+0x10a/0x1c0 drivers/net/tun.c:3390
 __fput+0x449/0xa70 fs/file_table.c:465
 task_work_run+0x1d1/0x260 kernel/task_work.c:227
 resume_user_mode_work+0x5e/0x80 include/linux/resume_user_mode.h:50
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x9a/0x120 kernel/entry/common.c:218
 do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3b5bf8e969
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:00007f3b5c2dfb88 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00000000000d14d6 RCX: 00007f3b5bf8e969
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f3b5c1b7ba0 R08: 0000000000000001 R09: 0000001e5c2dfe7f
R10: 00007f3b5be00000 R11: 0000000000000246 R12: 00007f3b5c1b5fac
R13: 00007f3b5c1b5fa0 R14: ffffffffffffffff R15: 00007f3b5c2dfca0
 </TASK>

The buggy address belongs to the variable:
 binder_devices+0x8/0x20

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x19d16
flags: 0xfff00000002000(reserved|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002000 ffffea0000674588 ffffea0000674588 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:
 ffffffff99d16700: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
 ffffffff99d16780: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
>ffffffff99d16800: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9
                                                          ^
 ffffffff99d16880: 00 00 f9 f9 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffff99d16900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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