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BUG: KASAN: slab-use-after-free in xfrm_state_find+0x2cf2/0x5400
Read of size 1 at addr ffff888027638c30 by task syz.2.5509/25409

CPU: 0 UID: 0 PID: 25409 Comm: syz.2.5509 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_find+0x2cf2/0x5400
 xfrm_resolve_and_create_bundle+0x768/0x2f80
 xfrm_lookup_with_ifid+0x58a/0x1a70
 xfrm_lookup_route+0x3c/0x1c0
 tipc_udp_xmit+0x1c3/0xaa0
 tipc_bearer_xmit_skb+0x2b3/0x400
 tipc_disc_timeout+0x580/0x6d0
 call_timer_fn+0x17e/0x5f0
 __run_timer_base+0x61a/0x860
 run_timer_softirq+0xb7/0x180
 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+0x4a/0x70
Code: 81 fa 00 01 00 00 75 35 83 b9 3c 16 00 00 00 74 2c 8b 91 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
RSP: 0000:ffffc90023107b20 EFLAGS: 00000246
RAX: ffffffff822e62d3 RBX: 0000000000012a45 RCX: ffff88811144b980
RDX: ffffc90020121000 RSI: 0000000000033196 RDI: 0000000000033197
RBP: ffffc90023107dd0 R08: ffff8881068eb3c7 R09: 1ffff11020d1d678
R10: dffffc0000000000 R11: ffffed1020d1d679 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000012a45 R15: 0000000000000001
 pfn_valid+0x473/0x490
 page_table_check_set+0x25/0x730
 set_ptes+0x231/0x240
 __handle_mm_fault+0x3a51/0x5440
 handle_mm_fault+0x40a/0x8e0
 do_user_addr_fault+0xa81/0x1390
 exc_page_fault+0x76/0xf0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7f19d3850c46
Code: f0 72 6e 48 63 cd 48 01 c1 49 39 4f 08 72 4c 8d 4d ff 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 <47> 0f b6 0c 08 45 84 c9 74 08 45 88 0c 00 49 8b 47 10 48 83 c0 01
RSP: 002b:00007f19d48054a0 EFLAGS: 00010206
RAX: 00000000005ea001 RBX: 00007f19d4805540 RCX: 0000000000000054
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007f19d48055e0
RBP: 0000000000000102 R08: 00007f19c9600000 R09: 00000000005ea000
R10: 0000000000000000 R11: 00007f19d4805550 R12: 0000000000000001
R13: 00007f19d3a2da20 R14: 0000000000000000 R15: 00007f19d48055e0
 </TASK>

Allocated by task 23395:
 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 ffff888027638900
 which belongs to the cache xfrm_state of size 928
The buggy address is located 816 bytes inside of
 freed 928-byte region [ffff888027638900, ffff888027638ca0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888027638000 pfn:0x27638
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 ffff888104d1bc80 dead000000000122 0000000000000000
raw: ffff888027638000 00000000800e0003 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff888104d1bc80 dead000000000122 0000000000000000
head: ffff888027638000 00000000800e0003 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea00009d8e01 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 9899, tgid 9898 (syz.2.876), ts 306684247641, free_ts 306601681748
 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 8873 tgid 8873 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 free_large_kmalloc+0x13a/0x1f0
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xec/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888027638b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888027638b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888027638c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff888027638c80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888027638d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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