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BUG: KASAN: slab-use-after-free in __xfrm_state_delete+0x696/0xca0
Write of size 8 at addr ffff888021dd9b30 by task kworker/u8:5/11760

CPU: 1 UID: 0 PID: 11760 Comm: kworker/u8:5 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_iv_send_outstanding_bat_ogm_packet
Call Trace:
 <IRQ>
 dump_stack_lvl+0x189/0x250
 print_report+0xca/0x240
 kasan_report+0x118/0x150
 __xfrm_state_delete+0x696/0xca0
 __xfrm_state_delete+0x87b/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:_raw_spin_unlock_irqrestore+0xa8/0x110
Code: 74 05 e8 6b 17 4b f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 53 bf 13 f6 65 8b 05 0c 12 24 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc90002d4f160 EFLAGS: 00000206
RAX: 93088d626ea71900 RBX: 0000000000000246 RCX: 93088d626ea71900
RDX: 0000000000000006 RSI: ffffffff8d9b77e3 RDI: 0000000000000001
RBP: ffffc90002d4f1f0 R08: ffffffff8fa38a37 R09: 1ffffffff1f47146
R10: dffffc0000000000 R11: fffffbfff1f47147 R12: dffffc0000000000
R13: ffffffff8e13f200 R14: ffffffff8e13f200 R15: 1ffff920005a9e2c
 rcu_preempt_deferred_qs_irqrestore+0x89c/0xce0
 rcu_read_unlock_special+0x3a2/0x4b0
 __rcu_read_unlock+0x84/0xe0
 unwind_next_frame+0x19ae/0x2390
 __unwind_start+0x5b9/0x760
 arch_stack_walk+0xe4/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 skb_clone+0x212/0x3a0
 batadv_iv_send_outstanding_bat_ogm_packet+0x5b5/0x7e0
 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 17030:
 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 5912:
 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 ffff888021dd9b00
 which belongs to the cache xfrm_state of size 928
The buggy address is located 48 bytes inside of
 freed 928-byte region [ffff888021dd9b00, ffff888021dd9ea0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888021dd8d80 pfn:0x21dd8
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff888104aeac80 dead000000000122 0000000000000000
raw: ffff888021dd8d80 00000000800e000b 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff888104aeac80 dead000000000122 0000000000000000
head: ffff888021dd8d80 00000000800e000b 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0000877601 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 6127, tgid 6126 (syz.2.92), ts 64318130987, free_ts 63411459626
 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 6098 tgid 6097 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 stack_depot_save_flags+0x436/0x860
 ref_tracker_alloc+0x18a/0x460
 neigh_parms_alloc+0x1f4/0x510
 ipv6_add_dev+0x42d/0x1370
 addrconf_notify+0x794/0x1010
 notifier_call_chain+0x1b6/0x3e0
 register_netdevice+0x1608/0x1ae0
 bond_newlink+0x60/0xb0
 rtnl_newlink_create+0x310/0xb00
 rtnl_newlink+0x16d6/0x1c70
 rtnetlink_rcv_msg+0x7cf/0xb70
 netlink_rcv_skb+0x208/0x470
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270

Memory state around the buggy address:
 ffff888021dd9a00: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888021dd9a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888021dd9b00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff888021dd9b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888021dd9c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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