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BUG: KASAN: slab-use-after-free in __xfrm_state_delete+0x666/0xca0
Write of size 8 at addr ffff88801f0ac4a8 by task kworker/u8:2/5713

CPU: 0 UID: 0 PID: 5713 Comm: kworker/u8:2 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: netns cleanup_net
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 print_report+0xca/0x240
 kasan_report+0x118/0x150
 __xfrm_state_delete+0x666/0xca0
 xfrm_state_flush+0x45f/0x770
 xfrm6_tunnel_net_exit+0x3f/0x100
 ops_undo_list+0x49a/0x990
 cleanup_net+0x4c5/0x800
 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 7031:
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 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
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 9:
 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 ffff88801f0ac480
 which belongs to the cache xfrm_state of size 928
The buggy address is located 40 bytes inside of
 freed 928-byte region [ffff88801f0ac480, ffff88801f0ac820)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88801f0ae880 pfn:0x1f0ac
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 ffff88801bbeb780 dead000000000122 0000000000000000
raw: ffff88801f0ae880 00000000800e000d 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801bbeb780 dead000000000122 0000000000000000
head: ffff88801f0ae880 00000000800e000d 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea00007c2b01 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 6287, tgid 6286 (syz.1.112), ts 74880211920, free_ts 74058534176
 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_acquire+0xf7/0xb20
 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 6248 tgid 6247 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 stack_depot_save_flags+0x436/0x860
 kasan_save_track+0x4f/0x80
 __kasan_krealloc+0xe7/0x140
 krealloc_noprof+0x1b8/0x340
 realloc_array+0x75/0x130
 check_stack_access_within_bounds+0x558/0x8b0
 check_mem_access+0x812/0x1cd0
 do_check+0x6657/0xe520
 do_check_common+0x1949/0x24f0
 bpf_check+0x1746a/0x1d2e0
 bpf_prog_load+0x1318/0x1930
 __sys_bpf+0x528/0x870
 __x64_sys_bpf+0x7c/0x90
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88801f0ac380: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88801f0ac400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88801f0ac480: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88801f0ac500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88801f0ac580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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