==================================================================
BUG: KASAN: slab-use-after-free in skb_clone+0x31d/0x3a0
Read of size 1 at addr ffff888123b16b80 by task ksoftirqd/0/15

CPU: 0 UID: 0 PID: 15 Comm: ksoftirqd/0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 print_report+0xca/0x240
 kasan_report+0x118/0x150
 skb_clone+0x31d/0x3a0
 maybe_deliver+0x98/0x160
 br_flood+0x31a/0x6a0
 br_handle_frame_finish+0x14b4/0x19b0
 br_handle_frame+0xb89/0x14c0
 __netif_receive_skb_core+0x10b9/0x4020
 __netif_receive_skb+0x72/0x380
 process_backlog+0x60e/0x14f0
 __napi_poll+0xc7/0x360
 net_rx_action+0x707/0xe30
 handle_softirqs+0x286/0x870
 run_ksoftirqd+0x9b/0x100
 smpboot_thread_fn+0x542/0xa60
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Allocated by task 5874:
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_node_noprof+0x1bb/0x3c0
 kmalloc_reserve+0xbd/0x290
 __alloc_skb+0x142/0x2d0
 arp_create+0x189/0x990
 batadv_bla_send_claim+0x16a/0xc50
 batadv_bla_periodic_work+0x605/0xac0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30

Freed by task 15:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kmem_cache_free+0x18f/0x400
 pskb_expand_head+0x382/0x1150
 batadv_skb_head_push+0x169/0x200
 batadv_interface_tx+0xc5c/0x14c0
 dev_hard_start_xmit+0x2d7/0x830
 __dev_queue_xmit+0x1b8d/0x3b50
 br_dev_queue_push_xmit+0x6c5/0x890
 NF_HOOK+0x320/0x3c0
 br_forward_finish+0xd3/0x130
 br_nf_forward_finish+0xa40/0xe60
 NF_HOOK+0x61b/0x6b0
 br_nf_forward+0xf49/0x18d0
 nf_hook_slow+0xc5/0x220
 NF_HOOK+0x215/0x3c0
 __br_forward+0x41e/0x600
 maybe_deliver+0xb5/0x160
 br_flood+0x31a/0x6a0
 br_handle_frame_finish+0x14b4/0x19b0
 br_handle_frame+0xb89/0x14c0
 __netif_receive_skb_core+0x10b9/0x4020
 __netif_receive_skb+0x72/0x380
 process_backlog+0x60e/0x14f0
 __napi_poll+0xc7/0x360
 net_rx_action+0x707/0xe30
 handle_softirqs+0x286/0x870
 run_ksoftirqd+0x9b/0x100
 smpboot_thread_fn+0x542/0xa60
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30

The buggy address belongs to the object at ffff888123b16a00
 which belongs to the cache skbuff_small_head of size 704
The buggy address is located 384 bytes inside of
 freed 704-byte region [ffff888123b16a00, ffff888123b16cc0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x123b14
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
ksm flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff8881012f9b40 ffffea00048f5700 dead000000000003
raw: 0000000000000000 0000000000120012 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff8881012f9b40 ffffea00048f5700 dead000000000003
head: 0000000000000000 0000000000120012 00000000f5000000 0000000000000000
head: 057ff00000000002 ffffea00048ec501 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 0, tgid 0 (swapper/1), ts 70321127736, free_ts 58081538538
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 allocate_slab+0x8a/0x370
 ___slab_alloc+0xbeb/0x1420
 kmem_cache_alloc_node_noprof+0x280/0x3c0
 kmalloc_reserve+0xbd/0x290
 __alloc_skb+0x142/0x2d0
 ndisc_alloc_skb+0x9f/0x480
 ndisc_send_rs+0x2b5/0x630
 addrconf_rs_timer+0x369/0x670
 call_timer_fn+0x17e/0x5f0
 __run_timer_base+0x61a/0x860
 run_timer_softirq+0xb7/0x180
 handle_softirqs+0x286/0x870
page last free pid 5909 tgid 5909 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 __put_partials+0x156/0x1a0
 put_cpu_partial+0x17c/0x250
 __slab_free+0x2d5/0x3c0
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 kmem_cache_alloc_node_noprof+0x1bb/0x3c0
 __alloc_skb+0x112/0x2d0
 mld_newpack+0x13c/0xc40
 add_grhead+0x5a/0x2a0
 add_grec+0x1452/0x1740
 mld_ifc_work+0x6ed/0xd60
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0

Memory state around the buggy address:
 ffff888123b16a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888123b16b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888123b16b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888123b16c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888123b16c80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================
