Commit 5ef6de7b authored by Fedor Pchelkin's avatar Fedor Pchelkin Committed by Felix Fietkau
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wifi: mt76: adjust BSS conf pointer handling 



Passing a BSS conf pointer to mt76_connac2_mac_tx_rate_val() currently has
two inconsistencies.

When called from mt76_connac2_mac_write_txwi(), BSS conf is got by
dereferencing a vif pointer.  A NULL vif isn't accounted for though the
function itself supposes it to be NULL and tries to handle this case in
previous checks.  This looks like a cosmetic change since the drivers
calling the function (namely, mt7915 and mt7921) set WANT_MONITOR_VIF flag
so judging by info->control.vif initialization inside ieee80211_tx_*()
routines it can't actually come as NULL here.

The same holds for the BSS conf pointer handling inside
mt76_connac2_mac_tx_rate_val().  It is dereferenced before being checked
for NULL.  The function supposes to handle the case so reorder the check
and dereference of the pointer.  Again, this looks like a syntax issue
only.

Found by Linux Verification Center (linuxtesting.org) with SVACE static
analysis tool.

Co-developed-by: default avatarMatvey Kovalev <matvey.kovalev@ispras.ru>
Signed-off-by: default avatarMatvey Kovalev <matvey.kovalev@ispras.ru>
Signed-off-by: default avatarFedor Pchelkin <pchelkin@ispras.ru>
Link: https://patch.msgid.link/20251027111843.38975-2-pchelkin@ispras.ru


Signed-off-by: default avatarFelix Fietkau <nbd@nbd.name>
parent cdb2941a

drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c

+11 −8
Original line number Diff line number Diff line
@@ -297,16 +297,18 @@ u16 mt76_connac2_mac_tx_rate_val(struct mt76_phy *mphy, 
				 struct ieee80211_bss_conf *conf,

				 bool beacon, bool mcast)

{

	struct mt76_vif_link *mvif = mt76_vif_conf_link(mphy->dev, conf->vif, conf);

	struct cfg80211_chan_def *chandef = mvif->ctx ?

					    &mvif->ctx->def : &mphy->chandef;

	u8 nss = 0, mode = 0, band = chandef->chan->band;

	int rateidx = 0, mcast_rate;

	int offset = 0;

	u8 nss = 0, mode = 0, band = NL80211_BAND_2GHZ;

	int rateidx = 0, offset = 0, mcast_rate;

	struct cfg80211_chan_def *chandef;

	struct mt76_vif_link *mvif;



	if (!conf)

		goto legacy;



	mvif = mt76_vif_conf_link(mphy->dev, conf->vif, conf);

	chandef = mvif->ctx ? &mvif->ctx->def : &mphy->chandef;

	band = chandef->chan->band;



	if (is_mt7921(mphy->dev)) {

		rateidx = ffs(conf->basic_rates) - 1;

		goto legacy;
@@ -584,8 +586,9 @@ void mt76_connac2_mac_write_txwi(struct mt76_dev *dev, __le32 *txwi, 
		struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;

		bool multicast = ieee80211_is_data(hdr->frame_control) &&

				 is_multicast_ether_addr(hdr->addr1);

		u16 rate = mt76_connac2_mac_tx_rate_val(mphy, &vif->bss_conf, beacon,

							multicast);

		u16 rate = mt76_connac2_mac_tx_rate_val(mphy,

							vif ? &vif->bss_conf : NULL,

							beacon, multicast);

		u32 val = MT_TXD6_FIXED_BW;



		/* hardware won't add HTC for mgmt/ctrl frame */