wifi: brcmfmac: slab-out-of-bounds read in brcmf_get_assoc_ies()

In the Linux kernel, the following vulnerability has been resolved:

wifi: brcmfmac: slab-out-of-bounds read in brcmf_get_assoc_ies()

Fix a slab-out-of-bounds read that occurs in kmemdup() called from
brcmf_get_assoc_ies().
The bug could occur when assoc_info->req_len, data from a URB provided
by a USB device, is bigger than the size of buffer which is defined as
WL_EXTRA_BUF_MAX.

Add the size check for req_len/resp_len of assoc_info.

Found by a modified version of syzkaller.

[ 46.592467][ T7] ==================================================================
[ 46.594687][ T7] BUG: KASAN: slab-out-of-bounds in kmemdup+0x3e/0x50
[ 46.596572][ T7] Read of size 3014656 at addr ffff888019442000 by task kworker/0:1/7
[ 46.598575][ T7]
[ 46.599157][ T7] CPU: 0 PID: 7 Comm: kworker/0:1 Tainted: G O 5.14.0+ #145
[ 46.601333][ T7] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
[ 46.604360][ T7] Workqueue: events brcmf_fweh_event_worker
[ 46.605943][ T7] Call Trace:
[ 46.606584][ T7] dump_stack_lvl+0x8e/0xd1
[ 46.607446][ T7] print_address_description.constprop.0.cold+0x93/0x334
[ 46.608610][ T7] ? kmemdup+0x3e/0x50
[ 46.609341][ T7] kasan_report.cold+0x79/0xd5
[ 46.610151][ T7] ? kmemdup+0x3e/0x50
[ 46.610796][ T7] kasan_check_range+0x14e/0x1b0
[ 46.611691][ T7] memcpy+0x20/0x60
[ 46.612323][ T7] kmemdup+0x3e/0x50
[ 46.612987][ T7] brcmf_get_assoc_ies+0x967/0xf60
[ 46.613904][ T7] ? brcmf_notify_vif_event+0x3d0/0x3d0
[ 46.614831][ T7] ? lock_chain_count+0x20/0x20
[ 46.615683][ T7] ? mark_lock.part.0+0xfc/0x2770
[ 46.616552][ T7] ? lock_chain_count+0x20/0x20
[ 46.617409][ T7] ? mark_lock.part.0+0xfc/0x2770
[ 46.618244][ T7] ? lock_chain_count+0x20/0x20
[ 46.619024][ T7] brcmf_bss_connect_done.constprop.0+0x241/0x2e0
[ 46.620019][ T7] ? brcmf_parse_configure_security.isra.0+0x2a0/0x2a0
[ 46.620818][ T7] ? __lock_acquire+0x181f/0x5790
[ 46.621462][ T7] brcmf_notify_connect_status+0x448/0x1950
[ 46.622134][ T7] ? rcu_read_lock_bh_held+0xb0/0xb0
[ 46.622736][ T7] ? brcmf_cfg80211_join_ibss+0x7b0/0x7b0
[ 46.623390][ T7] ? find_held_lock+0x2d/0x110
[ 46.623962][ T7] ? brcmf_fweh_event_worker+0x19f/0xc60
[ 46.624603][ T7] ? mark_held_locks+0x9f/0xe0
[ 46.625145][ T7] ? lockdep_hardirqs_on_prepare+0x3e0/0x3e0
[ 46.625871][ T7] ? brcmf_cfg80211_join_ibss+0x7b0/0x7b0
[ 46.626545][ T7] brcmf_fweh_call_event_handler.isra.0+0x90/0x100
[ 46.627338][ T7] brcmf_fweh_event_worker+0x557/0xc60
[ 46.627962][ T7] ? brcmf_fweh_call_event_handler.isra.0+0x100/0x100
[ 46.628736][ T7] ? rcu_read_lock_sched_held+0xa1/0xd0
[ 46.629396][ T7] ? rcu_read_lock_bh_held+0xb0/0xb0
[ 46.629970][ T7] ? lockdep_hardirqs_on_prepare+0x273/0x3e0
[ 46.630649][ T7] process_one_work+0x92b/0x1460
[ 46.631205][ T7] ? pwq_dec_nr_in_flight+0x330/0x330
[ 46.631821][ T7] ? rwlock_bug.part.0+0x90/0x90
[ 46.632347][ T7] worker_thread+0x95/0xe00
[ 46.632832][ T7] ? __kthread_parkme+0x115/0x1e0
[ 46.633393][ T7] ? process_one_work+0x1460/0x1460
[ 46.633957][ T7] kthread+0x3a1/0x480
[ 46.634369][ T7] ? set_kthread_struct+0x120/0x120
[ 46.634933][ T7] ret_from_fork+0x1f/0x30
[ 46.635431][ T7]
[ 46.635687][ T7] Allocated by task 7:
[ 46.636151][ T7] kasan_save_stack+0x1b/0x40
[ 46.636628][ T7] __kasan_kmalloc+0x7c/0x90
[ 46.637108][ T7] kmem_cache_alloc_trace+0x19e/0x330
[ 46.637696][ T7] brcmf_cfg80211_attach+0x4a0/0x4040
[ 46.638275][ T7] brcmf_attach+0x389/0xd40
[ 46.638739][ T7] brcmf_usb_probe+0x12de/0x1690
[ 46.639279][ T7] usb_probe_interface+0x2aa/0x760
[ 46.639820][ T7] really_probe+0x205/0xb70
[ 46.640342][ T7] __driver_probe_device+0
---truncated---