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BUG: KASAN: slab-use-after-free in xfrm_alloc_spi+0x570/0xf30
Read of size 4 at addr ffff888106b47b44 by task syz.2.5487/26767

CPU: 1 UID: 0 PID: 26767 Comm: syz.2.5487 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
 pfkey_getspi+0x7a8/0xee0
 pfkey_sendmsg+0xbfe/0x1090
 __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: 0033:0x7f8f2878ebe9
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:00007f8f296c2038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f8f289c6090 RCX: 00007f8f2878ebe9
RDX: 00000000200c00ca RSI: 00002000000001c0 RDI: 0000000000000003
RBP: 00007f8f28811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8f289c6128 R14: 00007f8f289c6090 R15: 00007ffdf5972168
 </TASK>

Allocated by task 23611:
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x37b/0x720
 xfrm_state_alloc+0x24/0x2f0
 xfrm_state_find+0x37d4/0x5400
 xfrm_resolve_and_create_bundle+0x768/0x2f80
 xfrm_lookup_with_ifid+0x2a7/0x1a70
 xfrm_lookup_route+0x3c/0x1c0
 __ip4_datagram_connect+0x9a5/0x1270
 __ip6_datagram_connect+0x9f0/0x1150
 ip6_datagram_connect_v6_only+0x63/0xa0
 __sys_connect+0x316/0x440
 __x64_sys_connect+0x7a/0x90
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5919:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kmem_cache_free+0x19a/0x6b0
 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 ffff888106b47a80
 which belongs to the cache xfrm_state of size 928
The buggy address is located 196 bytes inside of
 freed 928-byte region [ffff888106b47a80, ffff888106b47e20)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888106b44d80 pfn:0x106b44
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 ffff88810068c640 dead000000000122 0000000000000000
raw: ffff888106b44d80 00000000800e000b 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff88810068c640 dead000000000122 0000000000000000
head: ffff888106b44d80 00000000800e000b 00000000f5000000 0000000000000000
head: 057ff00000000002 ffffea00041ad101 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 6176, tgid 6175 (syz.2.61), ts 76633142416, free_ts 76526892969
 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
 __slab_alloc+0x55/0xa0
 kmem_cache_alloc_noprof+0x40d/0x720
 xfrm_state_alloc+0x24/0x2f0
 pfkey_add+0x6e4/0x2e00
 pfkey_sendmsg+0xbfe/0x1090
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
page last free pid 6176 tgid 6175 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_node_noprof+0x45f/0x760
 __alloc_skb+0x112/0x2d0
 inet6_ifmcaddr_notify+0xeb/0x1d0
 __ipv6_dev_mc_dec+0x2dc/0x330
 ipv6_mc_destroy_dev+0x33c/0x5a0
 addrconf_ifdown+0x139e/0x1880
 addrconf_notify+0x1bc/0x1010
 notifier_call_chain+0x1b6/0x3e0
 unregister_netdevice_many_notify+0x14d7/0x1ff0
 unregister_netdevice_queue+0x33c/0x380
 unregister_vlan_dev+0x346/0x4e0
 vlan_ioctl_handler+0x311/0x650

Memory state around the buggy address:
 ffff888106b47a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888106b47a80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888106b47b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff888106b47b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888106b47c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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