[PATCH AUTOSEL 6.11 060/244] wifi: iwlwifi: mvm: avoid NULL pointer dereference

[Sasha Levin <sashal@kernel.org>]

From: Miri Korenblit <miriam.rachel.korenblit@intel.com>

[ Upstream commit 557a6cd847645e667f3b362560bd7e7c09aac284 ]

iwl_mvm_tx_skb_sta() and iwl_mvm_tx_mpdu() verify that the mvmvsta
pointer is not NULL.
It retrieves this pointer using iwl_mvm_sta_from_mac80211, which is
dereferencing the ieee80211_sta pointer.
If sta is NULL, iwl_mvm_sta_from_mac80211 will dereference a NULL
pointer.
Fix this by checking the sta pointer before retrieving the mvmsta
from it. If sta is not NULL, then mvmsta isn't either.

Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Link: https://patch.msgid.link/20240825191257.880921ce23b7.I340052d70ab6d3410724ce955eb00da10e08188f@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/intel/iwlwifi/mvm/tx.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
index 7ff5ea5e7aca5..db926b2f4d8d5 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
@@ -1203,6 +1203,9 @@ static int iwl_mvm_tx_mpdu(struct iwl_mvm *mvm, struct sk_buff *skb,
 	bool is_ampdu = false;
 	int hdrlen;
 
+	if (WARN_ON_ONCE(!sta))
+		return -1;
+
 	mvmsta = iwl_mvm_sta_from_mac80211(sta);
 	fc = hdr->frame_control;
 	hdrlen = ieee80211_hdrlen(fc);
@@ -1210,9 +1213,6 @@ static int iwl_mvm_tx_mpdu(struct iwl_mvm *mvm, struct sk_buff *skb,
 	if (IWL_MVM_NON_TRANSMITTING_AP && ieee80211_is_probe_resp(fc))
 		return -1;
 
-	if (WARN_ON_ONCE(!mvmsta))
-		return -1;
-
 	if (WARN_ON_ONCE(mvmsta->deflink.sta_id == IWL_MVM_INVALID_STA))
 		return -1;
 
@@ -1343,7 +1343,7 @@ static int iwl_mvm_tx_mpdu(struct iwl_mvm *mvm, struct sk_buff *skb,
 int iwl_mvm_tx_skb_sta(struct iwl_mvm *mvm, struct sk_buff *skb,
 		       struct ieee80211_sta *sta)
 {
-	struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
+	struct iwl_mvm_sta *mvmsta;
 	struct ieee80211_tx_info info;
 	struct sk_buff_head mpdus_skbs;
 	struct ieee80211_vif *vif;
@@ -1352,9 +1352,11 @@ int iwl_mvm_tx_skb_sta(struct iwl_mvm *mvm, struct sk_buff *skb,
 	struct sk_buff *orig_skb = skb;
 	const u8 *addr3;
 
-	if (WARN_ON_ONCE(!mvmsta))
+	if (WARN_ON_ONCE(!sta))
 		return -1;
 
+	mvmsta = iwl_mvm_sta_from_mac80211(sta);
+
 	if (WARN_ON_ONCE(mvmsta->deflink.sta_id == IWL_MVM_INVALID_STA))
 		return -1;
 
-- 
2.43.0