wifi: ath11k: Ignore frags from uninitialized peer in dp.

wifi: ath11k: Ignore frags from uninitialized peer in dp.

[ Upstream commit a06bfb3c9f69f303692cdae87bc0899d2ae8b2a6 ]

When max virtual ap interfaces are configured in all the bands with
ACS and hostapd restart is done every 60s, a crash is observed at
random times.
In this certain scenario, a fragmented packet is received for
self peer, for which rx_tid and rx_frags are not initialized in
datapath. While handling this fragment, crash is observed as the
rx_frag list is uninitialised and when we walk in
ath11k_dp_rx_h_sort_frags, skb null leads to exception.

To address this, before processing received fragments we check
dp_setup_done flag is set to ensure that peer has completed its
dp peer setup for fragment queue, else ignore processing the
fragments.

Call trace:
  ath11k_dp_process_rx_err+0x550/0x1084 [ath11k]
  ath11k_dp_service_srng+0x70/0x370 [ath11k]
  0xffffffc009693a04
  __napi_poll+0x30/0xa4
  net_rx_action+0x118/0x270
  __do_softirq+0x10c/0x244
  irq_exit+0x64/0xb4
  __handle_domain_irq+0x88/0xac
  gic_handle_irq+0x74/0xbc
  el1_irq+0xf0/0x1c0
  arch_cpu_idle+0x10/0x18
  do_idle+0x104/0x248
  cpu_startup_entry+0x20/0x64
  rest_init+0xd0/0xdc
  arch_call_rest_init+0xc/0x14
  start_kernel+0x480/0x4b8
  Code: f9400281 f94066a2 91405021 b94a0023 (f9406401)

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.7.0.1-01744-QCAHKSWPL_SILICONZ-1

Signed-off-by: Harshitha Prem <quic_hprem@quicinc.com>
Signed-off-by: Nagarajan Maran <quic_nmaran@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230403184155.8670-2-quic_nmaran@quicinc.com
Signed-off-by: Sasha Levin <sashal@kernel.org>