==================================================================
BUG: KASAN: slab-use-after-free in __xfrm_state_delete+0x696/0xca0
Write of size 8 at addr ffff88811921fab0 by task kworker/u8:4/6135

CPU: 1 UID: 0 PID: 6135 Comm: kworker/u8:4 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
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <IRQ>
 dump_stack_lvl+0x189/0x250
 print_report+0xca/0x240
 kasan_report+0x118/0x150
 __xfrm_state_delete+0x696/0xca0
 xfrm_timer_handler+0x18f/0xa00
 __hrtimer_run_queues+0x52c/0xc60
 hrtimer_run_softirq+0x187/0x2b0
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__local_bh_enable_ip+0x135/0x1c0
Code: 8b e8 9f 2a f5 09 65 66 8b 05 4f 78 1b 11 66 85 c0 75 5a bf 01 00 00 00 e8 68 15 0b 00 e8 c3 6c 42 00 fb 65 8b 05 2b 78 1b 11 <85> c0 75 05 e8 e2 de ae ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00
RSP: 0018:ffffc900069378e0 EFLAGS: 00000282
RAX: 0000000080000000 RBX: 0000000000000201 RCX: 006ffdcce1140300
RDX: 0000000000000000 RSI: ffffffff8be33660 RDI: ffffffff8184e7fd
RBP: ffffc90006937978 R08: ffffffff8fa38537 R09: 1ffffffff1f470a6
R10: dffffc0000000000 R11: fffffbfff1f470a7 R12: ffffffff8b47f638
R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff92000d26f1c
 batadv_nc_purge_paths+0x318/0x3b0
 batadv_nc_worker+0x369/0x610
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Allocated by task 29617:
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 xfrm_state_alloc+0x24/0x2f0
 __find_acq_core+0x8a7/0x1c00
 xfrm_find_acq+0x78/0xa0
 xfrm_alloc_userspi+0x6b3/0xc90
 xfrm_user_rcv_msg+0x7a3/0xab0
 netlink_rcv_skb+0x208/0x470
 xfrm_netlink_rcv+0x79/0x90
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 16647:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kmem_cache_free+0x18f/0x400
 xfrm_state_gc_task+0x52d/0x6b0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

The buggy address belongs to the object at ffff88811921fa80
 which belongs to the cache xfrm_state of size 928
The buggy address is located 48 bytes inside of
 freed 928-byte region [ffff88811921fa80, ffff88811921fe20)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88811921d200 pfn:0x11921c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff88801c738b40 dead000000000122 0000000000000000
raw: ffff88811921d200 00000000800e000a 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff88801c738b40 dead000000000122 0000000000000000
head: ffff88811921d200 00000000800e000a 00000000f5000000 0000000000000000
head: 057ff00000000002 ffffea0004648701 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5945, tgid 5944 (syz.0.10), ts 49252844746, free_ts 49252683478
 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/0x1410
 kmem_cache_alloc_noprof+0x283/0x3c0
 xfrm_state_alloc+0x24/0x2f0
 xfrm_add_sa+0x17d1/0x4070
 xfrm_user_rcv_msg+0x7a3/0xab0
 netlink_rcv_skb+0x208/0x470
 xfrm_netlink_rcv+0x79/0x90
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
page last free pid 5945 tgid 5944 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 stack_depot_save_flags+0x436/0x860
 kasan_save_track+0x4f/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 skb_clone+0x212/0x3a0
 dev_queue_xmit_nit+0x416/0xcc0
 dev_hard_start_xmit+0x1be/0x830
 __dev_queue_xmit+0x1b8d/0x3b50
 __netlink_deliver_tap+0x5ad/0x850
 netlink_deliver_tap+0x19c/0x1b0
 netlink_sendskb+0x68/0x140
 netlink_unicast+0x397/0x9e0
 netlink_rcv_skb+0x28c/0x470
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30

Memory state around the buggy address:
 ffff88811921f980: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88811921fa00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88811921fa80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff88811921fb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88811921fb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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