[PATCH AUTOSEL 4.20 006/117] qtnfmac: fix error handling in control path

[PATCH AUTOSEL 4.20 006/117] qtnfmac: fix error handling in control path

[Sasha Levin]

From: Sergey Matyukevich <sergey.matyukevich.os@quantenna.com>

[ Upstream commit 1066bd193d681bda0fbacda9df351241a5ee04d9 ]

This patch fixes the following warnings:

- smatch
drivers/net/wireless/quantenna/qtnfmac/commands.c:132 qtnf_cmd_send_with_reply() warn: variable dereferenced before check 'resp' (see line 117)
drivers/net/wireless/quantenna/qtnfmac/commands.c:716  qtnf_cmd_get_sta_info() error: uninitialized symbol 'var_resp_len'.
drivers/net/wireless/quantenna/qtnfmac/commands.c:1668 qtnf_cmd_get_mac_info() error: uninitialized symbol 'var_data_len'.
drivers/net/wireless/quantenna/qtnfmac/commands.c:1697 qtnf_cmd_get_hw_info() error: uninitialized symbol 'info_len'.
drivers/net/wireless/quantenna/qtnfmac/commands.c:1753 qtnf_cmd_band_info_get() error: uninitialized symbol 'info_len'.
drivers/net/wireless/quantenna/qtnfmac/commands.c:1782 qtnf_cmd_send_get_phy_params() error: uninitialized symbol 'response_size'.
drivers/net/wireless/quantenna/qtnfmac/commands.c:2438 qtnf_cmd_get_chan_stats() error: uninitialized symbol 'var_data_len'.

- gcc-8.2.1
drivers/net/wireless/quantenna/qtnfmac/commands.c: In function 'qtnf_cmd_send_with_reply':
drivers/net/wireless/quantenna/qtnfmac/commands.c:133:54: error: 'resp' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sergey Matyukevich <sergey.matyukevich.os@quantenna.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 .../net/wireless/quantenna/qtnfmac/commands.c | 21 ++++++++++++-------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/net/wireless/quantenna/qtnfmac/commands.c b/drivers/net/wireless/quantenna/qtnfmac/commands.c
index bfdc1ad30c13..659e7649fe22 100644
--- a/drivers/net/wireless/quantenna/qtnfmac/commands.c
+++ b/drivers/net/wireless/quantenna/qtnfmac/commands.c
@@ -84,7 +84,7 @@ static int qtnf_cmd_send_with_reply(struct qtnf_bus *bus,
 				    size_t *var_resp_size)
 {
 	struct qlink_cmd *cmd;
-	const struct qlink_resp *resp;
+	struct qlink_resp *resp = NULL;
 	struct sk_buff *resp_skb = NULL;
 	u16 cmd_id;
 	u8 mac_id;
@@ -113,7 +113,12 @@ static int qtnf_cmd_send_with_reply(struct qtnf_bus *bus,
 	if (ret)
 		goto out;
 
-	resp = (const struct qlink_resp *)resp_skb->data;
+	if (WARN_ON(!resp_skb || !resp_skb->data)) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	resp = (struct qlink_resp *)resp_skb->data;
 	ret = qtnf_cmd_check_reply_header(resp, cmd_id, mac_id, vif_id,
 					  const_resp_size);
 	if (ret)
@@ -686,7 +691,7 @@ int qtnf_cmd_get_sta_info(struct qtnf_vif *vif, const u8 *sta_mac,
 	struct sk_buff *cmd_skb, *resp_skb = NULL;
 	struct qlink_cmd_get_sta_info *cmd;
 	const struct qlink_resp_get_sta_info *resp;
-	size_t var_resp_len;
+	size_t var_resp_len = 0;
 	int ret = 0;
 
 	cmd_skb = qtnf_cmd_alloc_new_cmdskb(vif->mac->macid, vif->vifid,
@@ -1650,7 +1655,7 @@ int qtnf_cmd_get_mac_info(struct qtnf_wmac *mac)
 {
 	struct sk_buff *cmd_skb, *resp_skb = NULL;
 	const struct qlink_resp_get_mac_info *resp;
-	size_t var_data_len;
+	size_t var_data_len = 0;
 	int ret = 0;
 
 	cmd_skb = qtnf_cmd_alloc_new_cmdskb(mac->macid, QLINK_VIFID_RSVD,
@@ -1680,8 +1685,8 @@ int qtnf_cmd_get_hw_info(struct qtnf_bus *bus)
 {
 	struct sk_buff *cmd_skb, *resp_skb = NULL;
 	const struct qlink_resp_get_hw_info *resp;
+	size_t info_len = 0;
 	int ret = 0;
-	size_t info_len;
 
 	cmd_skb = qtnf_cmd_alloc_new_cmdskb(QLINK_MACID_RSVD, QLINK_VIFID_RSVD,
 					    QLINK_CMD_GET_HW_INFO,
@@ -1709,9 +1714,9 @@ int qtnf_cmd_band_info_get(struct qtnf_wmac *mac,
 			   struct ieee80211_supported_band *band)
 {
 	struct sk_buff *cmd_skb, *resp_skb = NULL;
-	size_t info_len;
 	struct qlink_cmd_band_info_get *cmd;
 	struct qlink_resp_band_info_get *resp;
+	size_t info_len = 0;
 	int ret = 0;
 	u8 qband;
 
@@ -1764,8 +1769,8 @@ int qtnf_cmd_band_info_get(struct qtnf_wmac *mac,
 int qtnf_cmd_send_get_phy_params(struct qtnf_wmac *mac)
 {
 	struct sk_buff *cmd_skb, *resp_skb = NULL;
-	size_t response_size;
 	struct qlink_resp_phy_params *resp;
+	size_t response_size = 0;
 	int ret = 0;
 
 	cmd_skb = qtnf_cmd_alloc_new_cmdskb(mac->macid, 0,
@@ -2431,7 +2436,7 @@ int qtnf_cmd_get_chan_stats(struct qtnf_wmac *mac, u16 channel,
 	struct sk_buff *cmd_skb, *resp_skb = NULL;
 	struct qlink_cmd_get_chan_stats *cmd;
 	struct qlink_resp_get_chan_stats *resp;
-	size_t var_data_len;
+	size_t var_data_len = 0;
 	int ret = 0;
 
 	cmd_skb = qtnf_cmd_alloc_new_cmdskb(mac->macid, QLINK_VIFID_RSVD,
-- 
2.19.1

[PATCH AUTOSEL 4.20 105/117] ath10k: fix peer stats null pointer dereference

[Sasha Levin]

From: Zhi Chen <zhichen@codeaurora.org>

[ Upstream commit 2d3b55853b123c177037cf534c5aaa2650310094 ]

There was a race condition in SMP that an ath10k_peer was created but its
member sta was null. Following are procedures of ath10k_peer creation and
member sta access in peer statistics path.

    1. Peer creation:
        ath10k_peer_create()
            =>ath10k_wmi_peer_create()
                =>ath10k_wait_for_peer_created()
                ...

        # another kernel path, RX from firmware
        ath10k_htt_t2h_msg_handler()
        =>ath10k_peer_map_event()
                =>wake_up()
                # ar->peer_map[id] = peer //add peer to map

        #wake up original path from waiting
                ...
                # peer->sta = sta //sta assignment

    2.  RX path of statistics
        ath10k_htt_t2h_msg_handler()
            =>ath10k_update_per_peer_tx_stats()
                =>ath10k_htt_fetch_peer_stats()
                # peer->sta //sta accessing

Any access of peer->sta after peer was added to peer_map but before sta was
assigned could cause a null pointer issue. And because these two steps are
asynchronous, no proper lock can protect them. So both peer and sta need to
be checked before access.

Tested: QCA9984 with firmware ver 10.4-3.9.0.1-00005
Signed-off-by: Zhi Chen <zhichen@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/ath/ath10k/debugfs_sta.c | 2 +-
 drivers/net/wireless/ath/ath10k/htt_rx.c      | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/debugfs_sta.c b/drivers/net/wireless/ath/ath10k/debugfs_sta.c
index b09cdc699c69..38afbbd9fb44 100644
--- a/drivers/net/wireless/ath/ath10k/debugfs_sta.c
+++ b/drivers/net/wireless/ath/ath10k/debugfs_sta.c
@@ -71,7 +71,7 @@ void ath10k_sta_update_rx_tid_stats_ampdu(struct ath10k *ar, u16 peer_id, u8 tid
 	spin_lock_bh(&ar->data_lock);
 
 	peer = ath10k_peer_find_by_id(ar, peer_id);
-	if (!peer)
+	if (!peer || !peer->sta)
 		goto out;
 
 	arsta = (struct ath10k_sta *)peer->sta->drv_priv;
diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index ffec98f7be50..2c2761d04d01 100644
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -2832,7 +2832,7 @@ static void ath10k_htt_fetch_peer_stats(struct ath10k *ar,
 	rcu_read_lock();
 	spin_lock_bh(&ar->data_lock);
 	peer = ath10k_peer_find_by_id(ar, peer_id);
-	if (!peer) {
+	if (!peer || !peer->sta) {
 		ath10k_warn(ar, "Invalid peer id %d peer stats buffer\n",
 			    peer_id);
 		goto out;
@@ -2885,7 +2885,7 @@ static void ath10k_fetch_10_2_tx_stats(struct ath10k *ar, u8 *data)
 	rcu_read_lock();
 	spin_lock_bh(&ar->data_lock);
 	peer = ath10k_peer_find_by_id(ar, peer_id);
-	if (!peer) {
+	if (!peer || !peer->sta) {
 		ath10k_warn(ar, "Invalid peer id %d in peer stats buffer\n",
 			    peer_id);
 		goto out;
-- 
2.19.1