==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline]
BUG: KASAN: slab-use-after-free in __refcount_sub_and_test include/linux/refcount.h:389 [inline]
BUG: KASAN: slab-use-after-free in __refcount_dec_and_test include/linux/refcount.h:432 [inline]
BUG: KASAN: slab-use-after-free in refcount_dec_and_test include/linux/refcount.h:450 [inline]
BUG: KASAN: slab-use-after-free in skb_unref include/linux/skbuff.h:1292 [inline]
BUG: KASAN: slab-use-after-free in __sk_skb_reason_drop net/core/skbuff.c:1205 [inline]
BUG: KASAN: slab-use-after-free in sk_skb_reason_drop+0x3d/0x1b0 net/core/skbuff.c:1233
Write of size 4 at addr ffff8880770804a4 by task kworker/u32:9/1159

CPU: 1 UID: 0 PID: 1159 Comm: kworker/u32:9 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x156/0x4c9 mm/kasan/report.c:482
 kasan_report+0xdf/0x1a0 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:186 [inline]
 kasan_check_range+0x10f/0x1e0 mm/kasan/generic.c:200
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline]
 __refcount_sub_and_test include/linux/refcount.h:389 [inline]
 __refcount_dec_and_test include/linux/refcount.h:432 [inline]
 refcount_dec_and_test include/linux/refcount.h:450 [inline]
 skb_unref include/linux/skbuff.h:1292 [inline]
 __sk_skb_reason_drop net/core/skbuff.c:1205 [inline]
 sk_skb_reason_drop+0x3d/0x1b0 net/core/skbuff.c:1233
 kfree_skb_reason include/linux/skbuff.h:1322 [inline]
 dev_kfree_skb_any_reason net/core/dev.c:3463 [inline]
 dev_kfree_skb_any_reason+0x79/0x90 net/core/dev.c:3458
 dev_kfree_skb_any include/linux/netdevice.h:4194 [inline]
 team_dummy_transmit+0x1a/0x30 drivers/net/team/team_core.c:503
 team_xmit+0x34e/0x460 drivers/net/team/team_core.c:1683
 __netdev_start_xmit include/linux/netdevice.h:5273 [inline]
 netdev_start_xmit include/linux/netdevice.h:5282 [inline]
 xmit_one net/core/dev.c:3866 [inline]
 dev_hard_start_xmit+0x127/0x6c0 net/core/dev.c:3882
 __dev_queue_xmit+0x6dd/0x46f0 net/core/dev.c:4832
 dev_queue_xmit include/linux/netdevice.h:3381 [inline]
 vlan_dev_hard_start_xmit+0x3ac/0x5a0 net/8021q/vlan_dev.c:126
 __netdev_start_xmit include/linux/netdevice.h:5273 [inline]
 netdev_start_xmit include/linux/netdevice.h:5282 [inline]
 xmit_one net/core/dev.c:3866 [inline]
 dev_hard_start_xmit+0x127/0x6c0 net/core/dev.c:3882
 __dev_queue_xmit+0x6dd/0x46f0 net/core/dev.c:4832
 dev_queue_xmit include/linux/netdevice.h:3381 [inline]
 neigh_connected_output+0x3b7/0x5d0 net/core/neighbour.c:1623
 neigh_output include/net/neighbour.h:556 [inline]
 ip6_finish_output2+0xb0f/0x1cd0 net/ipv6/ip6_output.c:136
 __ip6_finish_output+0x3cd/0x10d0 net/ipv6/ip6_output.c:209
 ip6_finish_output net/ipv6/ip6_output.c:220 [inline]
 NF_HOOK_COND include/linux/netfilter.h:307 [inline]
 ip6_output+0x2aa/0xa60 net/ipv6/ip6_output.c:247
 dst_output include/net/dst.h:464 [inline]
 NF_HOOK include/linux/netfilter.h:318 [inline]
 NF_HOOK.constprop.0+0x114/0x8b0 include/linux/netfilter.h:312
 mld_sendpack+0x8f7/0xec0 net/ipv6/mcast.c:1855
 mld_send_initial_cr+0x219/0x320 net/ipv6/mcast.c:2271
 ipv6_mc_dad_complete+0xa7/0x1d0 net/ipv6/mcast.c:2279
 addrconf_dad_completed+0xd91/0xff0 net/ipv6/addrconf.c:4340
 addrconf_dad_work+0x83c/0x1360 net/ipv6/addrconf.c:4268
 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
 kthread+0x3b3/0x730 kernel/kthread.c:463
 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Allocated by task 1159:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_node_noprof+0x303/0x880 mm/slub.c:5315
 __alloc_skb+0x156/0x410 net/core/skbuff.c:679
 alloc_skb include/linux/skbuff.h:1383 [inline]
 mld_newpack.isra.0+0x18e/0xa20 net/ipv6/mcast.c:1775
 add_grhead+0x299/0x340 net/ipv6/mcast.c:1886
 add_grec+0x1380/0x1920 net/ipv6/mcast.c:2025
 mld_send_initial_cr+0x156/0x320 net/ipv6/mcast.c:2268
 ipv6_mc_dad_complete+0xa7/0x1d0 net/ipv6/mcast.c:2279
 addrconf_dad_completed+0xd91/0xff0 net/ipv6/addrconf.c:4340
 addrconf_dad_work+0x83c/0x1360 net/ipv6/addrconf.c:4268
 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
 kthread+0x3b3/0x730 kernel/kthread.c:463
 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Freed by task 1159:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2540 [inline]
 slab_free mm/slub.c:6674 [inline]
 kmem_cache_free+0x143/0x720 mm/slub.c:6785
 kfree_skbmem+0x19a/0x210 net/core/skbuff.c:1130
 __kfree_skb net/core/skbuff.c:1197 [inline]
 sk_skb_reason_drop+0x10f/0x1b0 net/core/skbuff.c:1234
 kfree_skb_reason include/linux/skbuff.h:1322 [inline]
 tcf_kfree_skb_list include/net/sch_generic.h:1127 [inline]
 __dev_xmit_skb net/core/dev.c:4273 [inline]
 __dev_queue_xmit+0x2a13/0x46f0 net/core/dev.c:4798
 dev_queue_xmit include/linux/netdevice.h:3381 [inline]
 team_dev_queue_xmit include/linux/if_team.h:239 [inline]
 team_queue_override_transmit drivers/net/team/team_core.c:815 [inline]
 team_xmit+0x191/0x460 drivers/net/team/team_core.c:1681
 __netdev_start_xmit include/linux/netdevice.h:5273 [inline]
 netdev_start_xmit include/linux/netdevice.h:5282 [inline]
 xmit_one net/core/dev.c:3866 [inline]
 dev_hard_start_xmit+0x127/0x6c0 net/core/dev.c:3882
 __dev_queue_xmit+0x6dd/0x46f0 net/core/dev.c:4832
 dev_queue_xmit include/linux/netdevice.h:3381 [inline]
 vlan_dev_hard_start_xmit+0x3ac/0x5a0 net/8021q/vlan_dev.c:126
 __netdev_start_xmit include/linux/netdevice.h:5273 [inline]
 netdev_start_xmit include/linux/netdevice.h:5282 [inline]
 xmit_one net/core/dev.c:3866 [inline]
 dev_hard_start_xmit+0x127/0x6c0 net/core/dev.c:3882
 __dev_queue_xmit+0x6dd/0x46f0 net/core/dev.c:4832
 dev_queue_xmit include/linux/netdevice.h:3381 [inline]
 neigh_connected_output+0x3b7/0x5d0 net/core/neighbour.c:1623
 neigh_output include/net/neighbour.h:556 [inline]
 ip6_finish_output2+0xb0f/0x1cd0 net/ipv6/ip6_output.c:136
 __ip6_finish_output+0x3cd/0x10d0 net/ipv6/ip6_output.c:209
 ip6_finish_output net/ipv6/ip6_output.c:220 [inline]
 NF_HOOK_COND include/linux/netfilter.h:307 [inline]
 ip6_output+0x2aa/0xa60 net/ipv6/ip6_output.c:247
 dst_output include/net/dst.h:464 [inline]
 NF_HOOK include/linux/netfilter.h:318 [inline]
 NF_HOOK.constprop.0+0x114/0x8b0 include/linux/netfilter.h:312
 mld_sendpack+0x8f7/0xec0 net/ipv6/mcast.c:1855
 mld_send_initial_cr+0x219/0x320 net/ipv6/mcast.c:2271
 ipv6_mc_dad_complete+0xa7/0x1d0 net/ipv6/mcast.c:2279
 addrconf_dad_completed+0xd91/0xff0 net/ipv6/addrconf.c:4340
 addrconf_dad_work+0x83c/0x1360 net/ipv6/addrconf.c:4268
 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
 kthread+0x3b3/0x730 kernel/kthread.c:463
 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

The buggy address belongs to the object at ffff8880770803c0
 which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 228 bytes inside of
 freed 240-byte region [ffff8880770803c0, ffff8880770804b0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888077080dc0 pfn:0x77080
head: order:1 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 ffff888040af8a00 ffffea0001326a80 0000000000000002
raw: ffff888077080dc0 0000000080190015 00000000f5000000 0000000000000000
head: 04fff00000000040 ffff888040af8a00 ffffea0001326a80 0000000000000002
head: ffff888077080dc0 0000000080190015 00000000f5000000 0000000000000000
head: 04fff00000000001 ffffea0001dc2001 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 60, tgid 60 (kworker/u32:3), ts 526114019878, free_ts 524743595814
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1e1/0x250 mm/page_alloc.c:1884
 prep_new_page mm/page_alloc.c:1892 [inline]
 get_page_from_freelist+0xe3d/0x2e10 mm/page_alloc.c:3945
 __alloc_frozen_pages_noprof+0x26c/0x2410 mm/page_alloc.c:5240
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486
 alloc_slab_page mm/slub.c:3075 [inline]
 allocate_slab mm/slub.c:3248 [inline]
 new_slab+0x2c4/0x440 mm/slub.c:3302
 ___slab_alloc+0xda3/0x1ca0 mm/slub.c:4656
 __slab_alloc.isra.0+0x63/0x110 mm/slub.c:4779
 __slab_alloc_node mm/slub.c:4855 [inline]
 slab_alloc_node mm/slub.c:5251 [inline]
 kmem_cache_alloc_node_noprof+0x51e/0x880 mm/slub.c:5315
 __alloc_skb+0x156/0x410 net/core/skbuff.c:679
 alloc_skb include/linux/skbuff.h:1383 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:818 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:875 [inline]
 nsim_dev_trap_report_work+0x2af/0xd10 drivers/net/netdevsim/dev.c:921
 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
 kthread+0x3b3/0x730 kernel/kthread.c:463
 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
page last free pid 0 tgid 0 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x822/0x1130 mm/page_alloc.c:2973
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core+0x7c0/0x15c0 kernel/rcu/tree.c:2857
 handle_softirqs+0x1ea/0x910 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697

Memory state around the buggy address:
 ffff888077080380: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
 ffff888077080400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888077080480: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
                               ^
 ffff888077080500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888077080580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
==================================================================