rtw89: cfo: check mac_id to avoid out-of-bounds

Somehow, hardware reports incorrect mac_id and pollute memory. Check index
before we access the array.

  UBSAN: array-index-out-of-bounds in rtw89/phy.c:2517:23
  index 188 is out of range for type 's32 [64]'
  CPU: 1 PID: 51550 Comm: irq/35-rtw89_pc Tainted: G           OE
  Call Trace:
   <IRQ>
   show_stack+0x52/0x58
   dump_stack_lvl+0x4c/0x63
   dump_stack+0x10/0x12
   ubsan_epilogue+0x9/0x45
   __ubsan_handle_out_of_bounds.cold+0x44/0x49
   ? __alloc_skb+0x92/0x1d0
   rtw89_phy_cfo_parse+0x44/0x7f [rtw89_core]
   rtw89_core_rx+0x261/0x871 [rtw89_core]
   ? __alloc_skb+0xee/0x1d0
   rtw89_pci_napi_poll+0x3fa/0x4ea [rtw89_pci]
   __napi_poll+0x33/0x1a0
   net_rx_action+0x126/0x260
   ? __queue_work+0x217/0x4c0
   __do_softirq+0xd9/0x315
   ? disable_irq_nosync+0x10/0x10
   do_softirq.part.0+0x6d/0x90
   </IRQ>
   <TASK>
   __local_bh_enable_ip+0x62/0x70
   rtw89_pci_interrupt_threadfn+0x182/0x1a6 [rtw89_pci]
   irq_thread_fn+0x28/0x60
   irq_thread+0xc8/0x190
   ? irq_thread_fn+0x60/0x60
   kthread+0x16b/0x190
   ? irq_thread_check_affinity+0xe0/0xe0
   ? set_kthread_struct+0x50/0x50
   ret_from_fork+0x22/0x30
   </TASK>

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220516005215.5878-4-pkshih@realtek.com

diff --git a/drivers/net/wireless/realtek/rtw89/phy.c b/drivers/net/wireless/realtek/rtw89/phy.c
index c9a4ae989ac7d64553306d8c3559eb43bc0617d1..79e4c28495c8019c6081c4c2b53f82d3df5fc616 100644 (file)
--- a/drivers/net/wireless/realtek/rtw89/phy.c
+++ b/drivers/net/wireless/realtek/rtw89/phy.c
@@ -2462,6 +2462,11 @@ void rtw89_phy_cfo_parse(struct rtw89_dev *rtwdev, s16 cfo_val,
        struct rtw89_cfo_tracking_info *cfo = &rtwdev->cfo_tracking;
        u8 macid = phy_ppdu->mac_id;
 
+       if (macid >= CFO_TRACK_MAX_USER) {
+               rtw89_warn(rtwdev, "mac_id %d is out of range\n", macid);
+               return;
+       }
+
        cfo->cfo_tail[macid] += cfo_val;
        cfo->cfo_cnt[macid]++;
        cfo->packet_count++;