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BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:1038 [inline]
BUG: KASAN: use-after-free in enqueue_timer+0xc3/0x5c0 kernel/time/timer.c:616
Write of size 8 at addr ffff88803acbdf40 by task ktimers/1/29

CPU: 1 UID: 0 PID: 29 Comm: ktimers/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xba/0x230 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 hlist_add_head include/linux/list.h:1038 [inline]
 enqueue_timer+0xc3/0x5c0 kernel/time/timer.c:616
 __mod_timer+0xb55/0xf60 kernel/time/timer.c:-1
 addrconf_mod_rs_timer+0x51/0xe0 net/ipv6/addrconf.c:331
 addrconf_rs_timer+0x49f/0x6d0 net/ipv6/addrconf.c:4052
 call_timer_fn+0x192/0x640 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x6a3/0x9f0 kernel/time/timer.c:2385
 run_timer_base kernel/time/timer.c:2394 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
 handle_softirqs+0x1de/0x6f0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 run_ktimerd+0x69/0x100 kernel/softirq.c:1138
 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88803acbd000 pfn:0x3acbd
flags: 0x80000000000000(node=0|zone=1)
raw: 0080000000000000 0000000000000000 00000000ffffffff 0000000000000000
raw: ffff88803acbd000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x446dc0(GFP_KERNEL_ACCOUNT|__GFP_ZERO|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_COMP), pid 7046, tgid 7046 (syz-executor), ts 209428303962, free_ts 294946446792
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2485
 ___kmalloc_large_node+0x4e/0x150 mm/slub.c:5160
 __kmalloc_large_node_noprof+0x18/0x90 mm/slub.c:5191
 __do_kmalloc_node mm/slub.c:5207 [inline]
 __kvmalloc_node_noprof+0x75/0x8e0 mm/slub.c:6711
 alloc_netdev_mqs+0xa6/0x11b0 net/core/dev.c:12019
 ieee80211_if_add+0x482/0x13a0 net/mac80211/iface.c:2239
 ieee80211_register_hw+0x36b8/0x4220 net/mac80211/main.c:1618
 mac80211_hwsim_new_radio+0x2efe/0x5210 drivers/net/wireless/virtual/mac80211_hwsim.c:5810
 hwsim_new_radio_nl+0xf35/0x1bd0 drivers/net/wireless/virtual/mac80211_hwsim.c:6504
 genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
page last free pid 3527 tgid 3527 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0xfe3/0x1170 mm/page_alloc.c:2978
 device_release+0x9e/0x1d0 drivers/base/core.c:-1
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x228/0x560 lib/kobject.c:737
 netdev_run_todo+0xc75/0xde0 net/core/dev.c:11720
 ieee80211_unregister_hw+0x128/0x2c0 net/mac80211/main.c:1701
 mac80211_hwsim_del_radio+0x28a/0x490 drivers/net/wireless/virtual/mac80211_hwsim.c:5916
 hwsim_exit_net+0xf02/0xfc0 drivers/net/wireless/virtual/mac80211_hwsim.c:6807
 ops_exit_list net/core/net_namespace.c:199 [inline]
 ops_undo_list+0x49f/0x940 net/core/net_namespace.c:252
 cleanup_net+0x56e/0x800 net/core/net_namespace.c:704
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff88803acbde00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88803acbde80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88803acbdf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff88803acbdf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88803acbe000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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