=====================================================
BUG: KMSAN: uninit-value in __ipv6_dev_mc_dec+0x68a/0xd30 net/ipv6/mcast.c:1014
 __ipv6_dev_mc_dec+0x68a/0xd30 net/ipv6/mcast.c:1014
 addrconf_leave_solict net/ipv6/addrconf.c:2254 [inline]
 __ipv6_ifa_notify+0xf97/0x1990 net/ipv6/addrconf.c:6299
 addrconf_ifdown+0x1c61/0x32e0 net/ipv6/addrconf.c:3978
 addrconf_notify+0x183/0x1d10 net/ipv6/addrconf.c:3777
 notifier_call_chain kernel/notifier.c:85 [inline]
 raw_notifier_call_chain+0xdd/0x410 kernel/notifier.c:453
 call_netdevice_notifiers_info+0x1ac/0x2b0 net/core/dev.c:2176
 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline]
 call_netdevice_notifiers net/core/dev.c:2228 [inline]
 dev_close_many+0x52a/0x8f0 net/core/dev.c:1731
 unregister_netdevice_many_notify+0x1106/0x4970 net/core/dev.c:11952
 unregister_netdevice_many net/core/dev.c:12046 [inline]
 unregister_netdevice_queue+0x3b1/0x600 net/core/dev.c:11889
 unregister_netdevice include/linux/netdevice.h:3374 [inline]
 __tun_detach+0x16c8/0x20c0 drivers/net/tun.c:620
 tun_detach drivers/net/tun.c:636 [inline]
 tun_chr_close+0xb7/0x290 drivers/net/tun.c:3390
 __fput+0x608/0x1040 fs/file_table.c:465
 delayed_fput+0x6f/0x100 fs/file_table.c:488
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xb97/0x1d90 kernel/workqueue.c:3319
 worker_thread+0xedf/0x1590 kernel/workqueue.c:3400
 kthread+0xd59/0xf00 kernel/kthread.c:464
 ret_from_fork+0x6e/0x90 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Local variable maddr.i created at:
 addrconf_leave_solict net/ipv6/addrconf.c:2248 [inline]
 __ipv6_ifa_notify+0xe6f/0x1990 net/ipv6/addrconf.c:6299
 addrconf_ifdown+0x1c61/0x32e0 net/ipv6/addrconf.c:3978

CPU: 1 UID: 0 PID: 24 Comm: kworker/1:0 Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0 PREEMPT(undef) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events delayed_fput
=====================================================