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BUG: KASAN: slab-use-after-free in __xfrm_state_delete+0x696/0xca0
Write of size 8 at addr ffff8880397c1fb0 by task syz.3.2807/16356

CPU: 1 UID: 0 PID: 16356 Comm: syz.3.2807 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:
 <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:__sanitizer_cov_trace_pc+0x5d/0x70
Code: 18 16 00 00 83 fa 02 75 21 48 8b 91 20 16 00 00 48 8b 32 48 8d 7e 01 8b 89 1c 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 <c3> cc cc cc cc cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90
RSP: 0018:ffffc90002ebf378 EFLAGS: 00000293
RAX: ffffffff822e4873 RBX: 8000000109b65007 RCX: ffff88803eff8000
RDX: 0000000000000000 RSI: 8000000109b65007 RDI: ffff8880236360c0
RBP: ffffc90002ebf650 R08: ffffea000426d947 R09: 1ffffd400084db28
R10: dffffc0000000000 R11: fffff9400084db29 R12: ffffea000426d958
R13: 1ffffd400084db2b R14: ffff8880236360c0 R15: 0000000000000000
 __page_table_check_pte_clear+0x13/0x70
 unmap_page_range+0x3445/0x4370
 unmap_vmas+0x399/0x580
 exit_mmap+0x248/0xb50
 __mmput+0x118/0x420
 exit_mm+0x1da/0x2c0
 do_exit+0x648/0x2300
 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
RIP: 0033:0x7f505458ebe9
Code: Unable to access opcode bytes at 0x7f505458ebbf.
RSP: 002b:00007f50554cc0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f50547c5fa8 RCX: 00007f505458ebe9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f50547c5fa8
RBP: 00007f50547c5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f50547c6038 R14: 00007ffc4681dd30 R15: 00007ffc4681de18
 </TASK>

Allocated by task 14396:
 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 974:
 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 ffff8880397c1f80
 which belongs to the cache xfrm_state of size 928
The buggy address is located 48 bytes inside of
 freed 928-byte region [ffff8880397c1f80, ffff8880397c2320)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880397c1f80 pfn:0x397c0
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 ffff888104acd780 dead000000000122 0000000000000000
raw: ffff8880397c1f80 00000000800e0007 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff888104acd780 dead000000000122 0000000000000000
head: ffff8880397c1f80 00000000800e0007 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0000e5f001 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 6395, tgid 6394 (syz.1.140), ts 67204110301, free_ts 67185598273
 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 6393 tgid 6386 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 stack_depot_save_flags+0x436/0x860
 kasan_save_track+0x4f/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_noprof+0x27a/0x4f0
 __register_sysctl_table+0xba1/0x1340
 neigh_sysctl_register+0x9a2/0xa80
 devinet_sysctl_register+0xad/0x200
 inetdev_init+0x2b4/0x500
 inetdev_event+0x301/0x15b0
 notifier_call_chain+0x1b6/0x3e0
 register_netdevice+0x1608/0x1ae0
 gtp_newlink+0xa2d/0xf30
 rtnl_newlink_create+0x310/0xb00
 rtnl_newlink+0x16d6/0x1c70
 rtnetlink_rcv_msg+0x7cf/0xb70

Memory state around the buggy address:
 ffff8880397c1e80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880397c1f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880397c1f80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff8880397c2000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880397c2080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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