netlink: 'syz.8.20786': attribute type 10 has an invalid length.
==================================================================
BUG: KASAN: slab-out-of-bounds in ieee80211_add_virtual_monitor+0xa42/0xce0
Read of size 1 at addr ffff8881a6007d50 by task syz.8.20786/22999

CPU: 0 UID: 0 PID: 22999 Comm: syz.8.20786 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
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+0xe8/0x150
 print_report+0xba/0x230
 kasan_report+0x117/0x150
 ieee80211_add_virtual_monitor+0xa42/0xce0
 ieee80211_do_stop+0x17d8/0x1ff0
 ieee80211_stop+0x1b1/0x240
 __dev_close_many+0x368/0x6d0
 __dev_change_flags+0x2cb/0x690
 netif_change_flags+0x88/0x1a0
 do_setlink+0xf82/0x4590
 rtnl_newlink+0x15a9/0x1be0
 rtnetlink_rcv_msg+0x7d5/0xbe0
 netlink_rcv_skb+0x232/0x4b0
 netlink_unicast+0x80f/0x9b0
 netlink_sendmsg+0x813/0xb40
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x4d7/0x810
 ___sys_sendmsg+0x2a5/0x360
 __x64_sys_sendmsg+0x1bd/0x2a0
 do_syscall_64+0xe2/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2b2f59acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2b30413028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f2b2f815fa0 RCX: 00007f2b2f59acb9
RDX: 0000000000000000 RSI: 0000200000000600 RDI: 0000000000000003
RBP: 00007f2b2f608bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2b2f816038 R14: 00007f2b2f815fa0 R15: 00007fff5c48df88
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8881a6007b80 pfn:0x1a6004
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88810c843b02
flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f8(unknown)
raw: 057ff00000000040 0000000000000000 dead000000000122 0000000000000000
raw: ffff8881a6007b80 0000000000000000 00000000f8000000 ffff88810c843b02
head: 057ff00000000040 0000000000000000 dead000000000122 0000000000000000
head: ffff8881a6007b80 0000000000000000 00000000f8000000 ffff88810c843b02
head: 057ff00000000002 ffffea0006980101 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 0x546dc0(GFP_USER|__GFP_ZERO|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_COMP|__GFP_ACCOUNT), pid 14876, tgid 14874 (syz.8.17340), ts 1165657875794, free_ts 1159537868332
 post_alloc_hook+0x231/0x280
 get_page_from_freelist+0x23a1/0x2440
 __alloc_frozen_pages_noprof+0x18d/0x380
 alloc_pages_mpol+0x232/0x4a0
 ___kmalloc_large_node+0x4e/0x150
 __kmalloc_large_node_noprof+0x18/0x90
 __kvmalloc_node_noprof+0x6e/0x8d0
 alloc_netdev_mqs+0xa6/0x11b0
 ieee80211_if_add+0x45c/0x1370
 ieee80211_add_iface+0xbb/0x580
 nl80211_new_interface+0x80a/0x1150
 genl_family_rcv_msg_doit+0x22a/0x330
 genl_rcv_msg+0x61c/0x7a0
 netlink_rcv_skb+0x232/0x4b0
 genl_rcv+0x28/0x40
 netlink_unicast+0x80f/0x9b0
page last free pid 5575 tgid 5575 stack trace:
 __free_frozen_pages+0xb81/0xce0
 __put_partials+0x146/0x170
 __slab_free+0x294/0x320
 qlist_free_all+0x97/0x100
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 kmem_cache_alloc_node_noprof+0x427/0x6f0
 __alloc_skb+0x1d7/0x390
 alloc_skb_with_frags+0xca/0x890
 sock_alloc_send_pskb+0x878/0x990
 unix_dgram_sendmsg+0x44e/0x17b0
 __sock_sendmsg+0x21c/0x270
 sock_write_iter+0x29e/0x3a0
 vfs_write+0x61d/0xb90
 ksys_write+0x150/0x270
 do_syscall_64+0xe2/0xf80

Memory state around the buggy address:
 ffff8881a6007c00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
 ffff8881a6007c80: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
>ffff8881a6007d00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
                                                 ^
 ffff8881a6007d80: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
 ffff8881a6007e00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
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