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BUG: KASAN: slab-use-after-free in xfrm_alloc_spi+0xe21/0xf30
Write of size 8 at addr ffff888108f089a0 by task syz.0.3499/18557

CPU: 1 UID: 0 PID: 18557 Comm: syz.0.3499 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+0xe21/0xf30
 xfrm_alloc_userspi+0x70b/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
RIP: 0033:0x7fd41a38ebe9
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:00007fd4185f6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fd41a5c5fa0 RCX: 00007fd41a38ebe9
RDX: 0000000000000000 RSI: 0000200000000580 RDI: 0000000000000003
RBP: 00007fd41a411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd41a5c6038 R14: 00007fd41a5c5fa0 R15: 00007ffe3c1f80b8
 </TASK>

Allocated by task 18222:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_noprof+0x27a/0x4f0
 tomoyo_encode+0x28b/0x550
 tomoyo_realpath_from_path+0x58d/0x5d0
 tomoyo_path_perm+0x213/0x4b0
 tomoyo_path_symlink+0xa3/0xe0
 security_path_symlink+0x177/0x380
 do_symlinkat+0x107/0x3f0
 __x64_sys_symlinkat+0x95/0xb0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 18222:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kfree+0x18e/0x440
 tomoyo_path_perm+0x3a2/0x4b0
 tomoyo_path_symlink+0xa3/0xe0
 security_path_symlink+0x177/0x380
 do_symlinkat+0x107/0x3f0
 __x64_sys_symlinkat+0x95/0xb0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888108f08980
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 32 bytes inside of
 freed 64-byte region [ffff888108f08980, ffff888108f089c0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888108f08900 pfn:0x108f08
flags: 0x57ff00000000200(workingset|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000200 ffff88801a4418c0 ffffea000412ad90 ffffea00041ab310
raw: ffff888108f08900 000000000020001d 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 53, tgid 53 (kworker/u10:3), ts 10438543996, free_ts 10438533216
 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
 __kmalloc_node_noprof+0x2fd/0x4e0
 __vmalloc_node_range_noprof+0x5a9/0x12f0
 __vmalloc_node_noprof+0xc2/0x110
 dup_task_struct+0x3e7/0x860
 copy_process+0x54b/0x3c00
 kernel_clone+0x21e/0x840
 user_mode_thread+0xdd/0x140
 call_usermodehelper_exec_work+0x5c/0x230
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
page last free pid 53 tgid 53 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 kasan_populate_vmalloc+0x18a/0x1a0
 alloc_vmap_area+0xd51/0x1490
 __get_vm_area_node+0x1f8/0x300
 __vmalloc_node_range_noprof+0x301/0x12f0
 __vmalloc_node_noprof+0xc2/0x110
 dup_task_struct+0x3e7/0x860
 copy_process+0x54b/0x3c00
 kernel_clone+0x21e/0x840
 user_mode_thread+0xdd/0x140
 call_usermodehelper_exec_work+0x5c/0x230
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

Memory state around the buggy address:
 ffff888108f08880: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
 ffff888108f08900: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff888108f08980: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                               ^
 ffff888108f08a00: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
 ffff888108f08a80: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
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