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BUG: KASAN: use-after-free in netdev_need_ops_lock include/net/netdev_lock.h:33 [inline]
BUG: KASAN: use-after-free in netdev_unlock_ops include/net/netdev_lock.h:47 [inline]
BUG: KASAN: use-after-free in __linkwatch_run_queue+0x880/0x8a0 net/core/link_watch.c:245
Read of size 8 at addr ffff88806bd10008 by task kworker/u32:4/81

CPU: 1 UID: 0 PID: 81 Comm: kworker/u32:4 Not tainted syzkaller #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:378 [inline]
 print_report+0xcd/0x630 mm/kasan/report.c:482
 kasan_report+0xe0/0x110 mm/kasan/report.c:595
 netdev_need_ops_lock include/net/netdev_lock.h:33 [inline]
 netdev_unlock_ops include/net/netdev_lock.h:47 [inline]
 __linkwatch_run_queue+0x880/0x8a0 net/core/link_watch.c:245
 linkwatch_event+0x8f/0xc0 net/core/link_watch.c:304
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
 kthread+0x3c2/0x780 kernel/kthread.c:463
 ret_from_fork+0x675/0x7d0 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:0x0 pfn:0x6bd10
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff88801b442dc0 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000
head: 04fff00000000040 ffff88801b442dc0 dead000000000122 0000000000000000
head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000
head: 04fff00000000003 ffffea0001af4401 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 62, tgid 62 (kworker/u32:3), ts 74058041058, free_ts 73988931675
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1850
 prep_new_page mm/page_alloc.c:1858 [inline]
 get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3884
 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5183
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:3031 [inline]
 allocate_slab mm/slub.c:3204 [inline]
 new_slab+0x24a/0x360 mm/slub.c:3258
 ___slab_alloc+0xdc4/0x1ae0 mm/slub.c:4628
 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4747
 __slab_alloc_node mm/slub.c:4823 [inline]
 slab_alloc_node mm/slub.c:5234 [inline]
 __do_kmalloc_node mm/slub.c:5603 [inline]
 __kmalloc_noprof+0x501/0x880 mm/slub.c:5616
 kmalloc_noprof include/linux/slab.h:961 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 ieee802_11_parse_elems_full+0x1db/0x3780 net/mac80211/parse.c:1011
 ieee802_11_parse_elems_crc net/mac80211/ieee80211_i.h:2470 [inline]
 ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2477 [inline]
 ieee80211_inform_bss+0x10b/0x1140 net/mac80211/scan.c:79
 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline]
 cfg80211_inform_single_bss_data+0x8ea/0x1df0 net/wireless/scan.c:2385
 cfg80211_inform_bss_data+0x22b/0x3be0 net/wireless/scan.c:3240
 cfg80211_inform_bss_frame_data+0x26f/0x750 net/wireless/scan.c:3331
 ieee80211_bss_info_update+0x310/0xab0 net/mac80211/scan.c:226
 ieee80211_scan_rx+0x4cf/0xb30 net/mac80211/scan.c:355
 __ieee80211_rx_handle_packet net/mac80211/rx.c:5194 [inline]
 ieee80211_rx_list+0x1b9b/0x2ab0 net/mac80211/rx.c:5447
page last free pid 6470 tgid 6467 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906
 device_release+0xa4/0x240 drivers/base/core.c:2565
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1e7/0x5a0 lib/kobject.c:737
 netdev_run_todo+0x7e9/0x1320 net/core/dev.c:11601
 rtnl_unlock net/core/rtnetlink.c:157 [inline]
 rtnl_nets_unlock net/core/rtnetlink.c:354 [inline]
 rtnl_newlink+0xe2a/0x2000 net/core/rtnetlink.c:4066
 rtnetlink_rcv_msg+0x95b/0xe90 net/core/rtnetlink.c:6954
 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xa98/0xc70 net/socket.c:2630
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684
 __sys_sendmsg+0x16d/0x220 net/socket.c:2716
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Memory state around the buggy address:
 ffff88806bd0ff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88806bd0ff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88806bd10000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff88806bd10080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88806bd10100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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