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Message-ID: <d9b3261a-549c-4db4-883c-75e17de3e1ee@quicinc.com>
Date: Fri, 2 Feb 2024 09:35:14 -0800
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Subject: Re: [PATCH] wifi: ath11k: initialize rx_mcs_80 and rx_mcs_160 before
 use
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To: Baochen Qiang <quic_bqiang@quicinc.com>, <ath11k@lists.infradead.org>
CC: <linux-wireless@vger.kernel.org>
References: <20240202023547.11141-1-quic_bqiang@quicinc.com>
From: Jeff Johnson <quic_jjohnson@quicinc.com>
In-Reply-To: <20240202023547.11141-1-quic_bqiang@quicinc.com>
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On 2/1/2024 6:35 PM, Baochen Qiang wrote:
> Currently in ath11k_peer_assoc_h_he() rx_mcs_80 and rx_mcs_160
> are used to calculate max_nss, see
> 	if (support_160)
> 		max_nss = min(rx_mcs_80, rx_mcs_160);
> 	else
> 		max_nss = rx_mcs_80;
> 
> Kernel test robot complains on uninitialized symbols:
> drivers/net/wireless/ath/ath11k/mac.c:2321 ath11k_peer_assoc_h_he() error: uninitialized symbol 'rx_mcs_80'.
> drivers/net/wireless/ath/ath11k/mac.c:2321 ath11k_peer_assoc_h_he() error: uninitialized symbol 'rx_mcs_160'.
> drivers/net/wireless/ath/ath11k/mac.c:2323 ath11k_peer_assoc_h_he() error: uninitialized symbol 'rx_mcs_80'.
> 
> This is because there are some code paths that never set them, so
> the assignment of max_nss can come from uninitialized variables.
> This could result in some unknown issues since a wrong peer_nss
> might be passed to firmware.
> 
> Change to initialize them to an invalid value at the beginning. This
> makes sense because even max_nss gets an invalid value, due to either
> or both of them being invalid, we can get an valid peer_nss with
> following guard:
> 	arg->peer_nss = min(sta->deflink.rx_nss, max_nss)
> 
> Tested-on: WCN6855 hw2.1 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.23
> 
> Fixes: 3db26ecf7114 ("ath11k: calculate the correct NSS of peer for HE capabilities")
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202401311243.NyXwWZxP-lkp@intel.com/
> Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>