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BUG: KASAN: slab-use-after-free in __xfrm_state_delete+0x696/0xca0
Write of size 8 at addr ffff8880228a0930 by task syz.2.938/8353

CPU: 1 UID: 0 PID: 8353 Comm: syz.2.938 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:__get_pfnblock_flags_mask+0xb4/0x240
Code: 01 00 00 49 69 ed 80 07 00 00 4d 8d 2c 2c 49 81 c5 90 00 00 00 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 <74> 08 4c 89 ef e8 52 05 0e 00 49 8b 5d 00 4c 39 f3 0f 87 4b 01 00
RSP: 0018:ffffc90006ca7aa8 EFLAGS: 00000246
RAX: 1ffff1100bfff782 RBX: ff000fffffffffff RCX: dffffc0000000000
RDX: 0000000000000017 RSI: 000000000003d34a RDI: ffffea0000f4d280
RBP: 0000000000000780 R08: dffffc0000000000 R09: 0000000000000000
R10: ffffed1007a69400 R11: fffffbfff1f47407 R12: ffff88805fffb400
R13: ffff88805fffbc10 R14: 000000000003d34a R15: ffffea0000f4d280
 __free_frozen_pages+0x5cf/0xd30
 pagetable_dtor_free+0x2d2/0x3b0
 __mmdrop+0xb5/0x570
 exit_mm+0x1da/0x2c0
 do_exit+0x648/0x2300
 do_group_exit+0x21c/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x21f7/0x2200
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0d19f8eba9
Code: Unable to access opcode bytes at 0x7f0d19f8eb7f.
RSP: 002b:00007fffdf8bf6c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0d19f8eba9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fffdf8bf72c R08: 00000005df8bf7bf R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000143
R13: 00000000000927c0 R14: 0000000000023a83 R15: 00007fffdf8bf780
 </TASK>

Allocated by task 8330:
 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 ffff8880228a0900
 which belongs to the cache xfrm_state of size 928
The buggy address is located 48 bytes inside of
 freed 928-byte region [ffff8880228a0900, ffff8880228a0ca0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x228a0
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 ffff88801d74c280 dead000000000122 0000000000000000
raw: 0000000000000000 00000000800e000e 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801d74c280 dead000000000122 0000000000000000
head: 0000000000000000 00000000800e000e 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea00008a2801 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 6001, tgid 6000 (syz.0.37), ts 69713566764, free_ts 69623125698
 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/0x1420
 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 5833 tgid 5833 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 __slab_free+0x303/0x3c0
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 kmem_cache_alloc_node_noprof+0x1bb/0x3c0
 __alloc_skb+0x112/0x2d0
 tcp_stream_alloc_skb+0x3d/0x340
 tcp_sendmsg_locked+0xf38/0x5620
 tcp_sendmsg+0x2f/0x50
 __sock_sendmsg+0x19c/0x270
 sock_write_iter+0x258/0x330
 vfs_write+0x5c9/0xb30
 ksys_write+0x145/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff8880228a0800: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880228a0880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880228a0900: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff8880228a0980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880228a0a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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