netlink: 12 bytes leftover after parsing attributes in process `syz.4.795'.
==================================================================
BUG: KASAN: slab-out-of-bounds in __xfrm_state_lookup+0x6ad/0x8d0
Read of size 2 at addr ffff88802a31ee42 by task syz.4.795/9330

CPU: 0 UID: 0 PID: 9330 Comm: syz.4.795 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_lookup+0x6ad/0x8d0
 xfrm_state_lookup+0x11e/0x1e0
 xfrm_user_state_lookup+0x231/0x370
 xfrm_get_sa+0x93/0x290
 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: 0033:0x7ff76518eba9
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:00007ff765fcf038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff7653d5fa0 RCX: 00007ff76518eba9
RDX: 0000000000000010 RSI: 0000200000000040 RDI: 0000000000000005
RBP: 00007ff765211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff7653d6038 R14: 00007ff7653d5fa0 R15: 00007ffffe264e08
 </TASK>

Allocated by task 9193:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x230/0x3d0
 __genradix_ptr_alloc+0x352/0x4a0
 __genradix_prealloc+0x44/0x90
 sctp_stream_init+0x14b/0x440
 sctp_association_new+0x10dd/0x25f0
 sctp_connect_new_asoc+0x2c5/0x690
 __sctp_connect+0x5ba/0xd50
 sctp_getsockopt_connectx3+0x2c4/0x440
 sctp_getsockopt+0x98a/0xb60
 do_sock_getsockopt+0x372/0x450
 __x64_sys_getsockopt+0x1a5/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 9193:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kfree+0x18e/0x440
 genradix_free_recurse+0x5d/0xa0
 genradix_free_recurse+0x5d/0xa0
 sctp_stream_free+0xd5/0x110
 sctp_association_free+0x26d/0x7f0
 sctp_do_sm+0x3eba/0x5a20
 sctp_primitive_SHUTDOWN+0x98/0xc0
 sctp_close+0x409/0x900
 inet_release+0x144/0x190
 sock_close+0xc3/0x240
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 get_signal+0x11ed/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802a31ec00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 66 bytes to the right of
 allocated 512-byte region [ffff88802a31ec00, ffff88802a31ee00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2a31c
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 ffff88801a441c80 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801a441c80 dead000000000122 0000000000000000
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0000a8c701 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 9193, tgid 9187 (syz.5.759), ts 172178272964, free_ts 171052538470
 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
 __kmalloc_cache_noprof+0x296/0x3d0
 __genradix_ptr_alloc+0x352/0x4a0
 __genradix_prealloc+0x44/0x90
 sctp_stream_init+0x14b/0x440
 sctp_association_new+0x10dd/0x25f0
 sctp_connect_new_asoc+0x2c5/0x690
 __sctp_connect+0x5ba/0xd50
 sctp_getsockopt_connectx3+0x2c4/0x440
 sctp_getsockopt+0x98a/0xb60
 do_sock_getsockopt+0x372/0x450
page last free pid 9106 tgid 9106 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_noprof+0x1c1/0x3c0
 vm_area_dup+0x2b/0x680
 __split_vma+0x1a9/0xa00
 vma_modify+0x13b3/0x1970
 vma_modify_flags+0x1e8/0x230
 mprotect_fixup+0x407/0x9c0
 do_mprotect_pkey+0x8cd/0xce0
 __x64_sys_mprotect+0x80/0x90
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88802a31ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802a31ed80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802a31ee00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                           ^
 ffff88802a31ee80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802a31ef00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
