wifi: ath12k: fix possible out-of-bound read in ath12k_htt_pull_ppdu_stats()

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: wifi: ath12k: fix possible out-of-bound read in ath12k_htt_pull_ppdu_stats() len is extracted from HTT message and could be an unexpected value in case errors happen, so add validation before using to avoid possible out-of-bound read in the following message iteration and parsing. The same issue also applies to ppdu_info->ppdu_stats.common.num_users, so validate it before using too. These are found during code review. Compile test only.

References

• https://git.kernel.org/stable/c/79527c21a3ce04cffc35ea54f74ee087e532be57
• https://git.kernel.org/stable/c/c9e44111da221246efb2e623ae1be40a5cf6542c
• https://git.kernel.org/stable/c/1bc44a505a229bb1dd4957e11aa594edeea3690e