netlink: 15478 bytes leftover after parsing attributes in process `syz.4.714'.
==================================================================
BUG: KASAN: slab-use-after-free in xfrm_alloc_spi+0x570/0xf30
Read of size 4 at addr ffff88811c2ec0c4 by task syz.4.714/8547

CPU: 0 UID: 0 PID: 8547 Comm: syz.4.714 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
 xfrm_alloc_spi+0x570/0xf30
 xfrm_alloc_userspi+0x70b/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
RIP: 0033:0x7f6261f8ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6262e23038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f62621c5fa0 RCX: 00007f6261f8ebe9
RDX: 0000000000048000 RSI: 0000200000000000 RDI: 0000000000000003
RBP: 00007f6262011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f62621c6038 R14: 00007f62621c5fa0 R15: 00007fff160a5ec8
 </TASK>

Allocated by task 7609:
 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 5881:
 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 ffff88811c2ec000
 which belongs to the cache xfrm_state of size 928
The buggy address is located 196 bytes inside of
 freed 928-byte region [ffff88811c2ec000, ffff88811c2ec3a0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88811c2edb00 pfn:0x11c2ec
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 ffff88801d7ec3c0 dead000000000122 0000000000000000
raw: ffff88811c2edb00 00000000800e0009 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff88801d7ec3c0 dead000000000122 0000000000000000
head: ffff88811c2edb00 00000000800e0009 00000000f5000000 0000000000000000
head: 057ff00000000002 ffffea000470bb01 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 6022, tgid 6018 (syz.1.24), ts 59835395741, free_ts 59795214000
 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 5978 tgid 5970 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 free_large_kmalloc+0x13a/0x1f0
 free_netdev+0x3e2/0x700
 netdev_run_todo+0xd0c/0xea0
 tun_chr_close+0x13c/0x1c0
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 do_exit+0x6b5/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1286/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88811c2ebf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88811c2ec000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88811c2ec080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff88811c2ec100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88811c2ec180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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