Patch "wifi: iwlwifi: mvm: avoid NULL pointer dereference" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    wifi: iwlwifi: mvm: avoid NULL pointer dereference

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     wifi-iwlwifi-mvm-avoid-null-pointer-dereference.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 6f4454f0c200b3c3ec4f7f15c51163eabf93b7ee
Author: Miri Korenblit <miriam.rachel.korenblit@xxxxxxxxx>
Date:   Sun Aug 25 19:17:09 2024 +0300

    wifi: iwlwifi: mvm: avoid NULL pointer dereference
    
    [ 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@xxxxxxxxx>
    Reviewed-by: Johannes Berg <johannes.berg@xxxxxxxxx>
    Link: https://patch.msgid.link/20240825191257.880921ce23b7.I340052d70ab6d3410724ce955eb00da10e08188f@changeid
    Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
index 3adb1acc07191..ce5f2bdde1388 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
@@ -1145,6 +1145,9 @@ 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);
@@ -1152,9 +1155,6 @@ 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;
 
@@ -1285,7 +1285,7 @@ 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;
@@ -1294,9 +1294,11 @@ 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;