==================================================================
BUG: KASAN: slab-use-after-free in __hlist_del include/linux/list.h:994 [inline]
BUG: KASAN: slab-use-after-free in detach_timer+0x12e/0x300 kernel/time/timer.c:891
Write of size 8 at addr ffff88804d17df40 by task ktimers/0/16

CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 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_del include/linux/list.h:994 [inline]
 detach_timer+0x12e/0x300 kernel/time/timer.c:891
 expire_timers kernel/time/timer.c:1782 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x624/0x9f0 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>

Allocated by task 29:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4501 [inline]
 slab_alloc_node mm/slub.c:4830 [inline]
 kmem_cache_alloc_node_noprof+0x22a/0x6e0 mm/slub.c:4882
 kmalloc_reserve net/core/skbuff.c:613 [inline]
 __alloc_skb+0x27d/0x7d0 net/core/skbuff.c:713
 __netdev_alloc_skb+0xc0/0x4b0 net/core/skbuff.c:775
 netdev_alloc_skb include/linux/skbuff.h:3485 [inline]
 dev_alloc_skb include/linux/skbuff.h:3498 [inline]
 __ieee80211_beacon_get+0xca4/0x1860 net/mac80211/tx.c:5656
 ieee80211_beacon_get_tim+0xbd/0x2c0 net/mac80211/tx.c:5778
 ieee80211_beacon_get include/net/mac80211.h:5720 [inline]
 mac80211_hwsim_beacon_tx+0x3c5/0x870 drivers/net/wireless/virtual/mac80211_hwsim.c:2361
 __iterate_interfaces+0x2ab/0x590 net/mac80211/util.c:760
 ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:796
 mac80211_hwsim_beacon+0xbb/0x180 drivers/net/wireless/virtual/mac80211_hwsim.c:2395
 __run_hrtimer kernel/time/hrtimer.c:1785 [inline]
 __hrtimer_run_queues+0x55f/0xda0 kernel/time/hrtimer.c:1849
 hrtimer_run_softirq+0x192/0x5d0 kernel/time/hrtimer.c:1866
 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

Freed by task 29:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2687 [inline]
 slab_free mm/slub.c:6124 [inline]
 kmem_cache_free+0x185/0x6b0 mm/slub.c:6254
 skb_kfree_head net/core/skbuff.c:1087 [inline]
 skb_free_head net/core/skbuff.c:1101 [inline]
 skb_release_data+0x6c3/0x940 net/core/skbuff.c:1128
 skb_release_all net/core/skbuff.c:1203 [inline]
 __kfree_skb+0x5d/0x210 net/core/skbuff.c:1217
 mac80211_hwsim_beacon_tx+0x3e8/0x870 drivers/net/wireless/virtual/mac80211_hwsim.c:2365
 __iterate_interfaces+0x2ab/0x590 net/mac80211/util.c:760
 ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:796
 mac80211_hwsim_beacon+0xbb/0x180 drivers/net/wireless/virtual/mac80211_hwsim.c:2395
 __run_hrtimer kernel/time/hrtimer.c:1785 [inline]
 __hrtimer_run_queues+0x55f/0xda0 kernel/time/hrtimer.c:1849
 hrtimer_run_softirq+0x192/0x5d0 kernel/time/hrtimer.c:1866
 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

The buggy address belongs to the object at ffff88804d17dd40
 which belongs to the cache skbuff_small_head of size 704
The buggy address is located 512 bytes inside of
 freed 704-byte region [ffff88804d17dd40, ffff88804d17e000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4d17c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x80000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000040 ffff888140419dc0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000130013 00000000f5000000 0000000000000000
head: 0080000000000040 ffff888140419dc0 dead000000000100 dead000000000122
head: 0000000000000000 0000000000130013 00000000f5000000 0000000000000000
head: 0080000000000002 ffffea0001345f01 00000000ffffffff 00000000ffffffff
head: 00000007fee09a2f 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5935, tgid 5935 (udevd), ts 133132152590, free_ts 131674286686
 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_slab_page mm/slub.c:3255 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3444
 new_slab mm/slub.c:3502 [inline]
 refill_objects+0x334/0x3c0 mm/slub.c:7134
 refill_sheaf mm/slub.c:2804 [inline]
 __pcs_replace_empty_main+0x328/0x5f0 mm/slub.c:4578
 alloc_from_pcs mm/slub.c:4681 [inline]
 slab_alloc_node mm/slub.c:4815 [inline]
 kmem_cache_alloc_node_noprof+0x4f4/0x6e0 mm/slub.c:4882
 kmalloc_reserve net/core/skbuff.c:613 [inline]
 __alloc_skb+0x27d/0x7d0 net/core/skbuff.c:713
 netlink_sendmsg+0x5d4/0xb40 net/netlink/af_netlink.c:1869
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xa4e/0xac0 net/socket.c:2592
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2683 [inline]
 __se_sys_sendmsg net/socket.c:2681 [inline]
 __x64_sys_sendmsg+0x1c3/0x2a0 net/socket.c:2681
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 1371 tgid 1371 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
 stack_depot_save_flags+0x40e/0x810 lib/stackdepot.c:735
 kasan_save_stack mm/kasan/common.c:58 [inline]
 kasan_save_track+0x4f/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x3a6/0x690 mm/slub.c:5339
 kmalloc_noprof include/linux/slab.h:962 [inline]
 kzalloc_noprof include/linux/slab.h:1200 [inline]
 kobject_uevent_env+0x28f/0x9e0 lib/kobject_uevent.c:540
 device_del+0x754/0x900 drivers/base/core.c:3896
 rfkill_unregister+0xc3/0x230 net/rfkill/core.c:1143
 wiphy_unregister+0x25e/0xb20 net/wireless/core.c:1175
 ieee80211_unregister_hw+0x1e2/0x2c0 net/mac80211/main.c:1713
 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

Memory state around the buggy address:
 ffff88804d17de00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88804d17de80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88804d17df00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff88804d17df80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88804d17e000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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