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BUG: KASAN: slab-use-after-free in xfrm_state_find+0x2cf2/0x5400
Read of size 1 at addr ffff8880323bc7b0 by task syz.3.1509/10557

CPU: 0 UID: 0 PID: 10557 Comm: syz.3.1509 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_state_find+0x2cf2/0x5400
 xfrm_resolve_and_create_bundle+0x768/0x2f80
 xfrm_lookup_with_ifid+0x58a/0x1a70
 icmp_route_lookup+0x3ab/0x870
 __icmp_send+0xd0e/0x12d0
 ip_options_compile+0x80/0xb0
 ip_rcv_finish_core+0xaa2/0x1c00
 ip_rcv_finish+0x14c/0x2f0
 NF_HOOK+0x30c/0x3a0
 __netif_receive_skb+0x143/0x380
 netif_receive_skb+0x1cb/0x790
 tun_rx_batched+0x1b9/0x730
 tun_get_user+0x2aa2/0x3e20
 tun_chr_write_iter+0x113/0x200
 vfs_write+0x5c9/0xb30
 ksys_write+0x145/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f03f8f8d69f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007f03f9e46000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f03f91b5fa0 RCX: 00007f03f8f8d69f
RDX: 0000000000000042 RSI: 0000200000000100 RDI: 00000000000000c8
RBP: 00007f03f9011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000042 R11: 0000000000000293 R12: 0000000000000000
R13: 00007f03f91b6038 R14: 00007f03f91b5fa0 R15: 00007ffc36ad3c98
 </TASK>

Allocated by task 8372:
 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 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 ffff8880323bc480
 which belongs to the cache xfrm_state of size 928
The buggy address is located 816 bytes inside of
 freed 928-byte region [ffff8880323bc480, ffff8880323bc820)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880323bcd80 pfn:0x323bc
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 ffff888104e81280 dead000000000122 0000000000000000
raw: ffff8880323bcd80 00000000800e000b 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff888104e81280 dead000000000122 0000000000000000
head: ffff8880323bcd80 00000000800e000b 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0000c8ef01 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 7122, tgid 7118 (syz.2.428), ts 109455105250, free_ts 109313961627
 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
 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
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 7111 tgid 7110 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
 find_tree_dqentry+0x6f2/0x1070
 find_tree_dqentry+0x6c4/0x1070
 find_tree_dqentry+0x6c4/0x1070
 find_tree_dqentry+0x6c4/0x1070
 qtree_read_dquot+0x564/0x800
 v2_read_dquot+0x116/0x1d0
 dquot_acquire+0x184/0x620
 ext4_acquire_dquot+0x2e9/0x4c0
 dqget+0x7b1/0xf10
 __dquot_initialize+0x3b3/0xcb0
 ext4_unlink+0x197/0x5d0

Memory state around the buggy address:
 ffff8880323bc680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880323bc700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880323bc780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff8880323bc800: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880323bc880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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