wifi: mac80211_hwsim: use 32-bit skb cookie
authorJohannes Berg <johannes.berg@intel.com>
Wed, 13 Jul 2022 19:16:45 +0000 (21:16 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 17 Aug 2022 12:22:46 +0000 (14:22 +0200)
commit cc5250cdb43d444061412df7fae72d2b4acbdf97 upstream.

We won't really have enough skbs to need a 64-bit cookie,
and on 32-bit platforms storing the 64-bit cookie into the
void *rate_driver_data doesn't work anyway. Switch back to
using just a 32-bit cookie and uintptr_t for the type to
avoid compiler warnings about all this.

Fixes: 4ee186fa7e40 ("wifi: mac80211_hwsim: fix race condition in pending packet")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Cc: Jeongik Cha <jeongik@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/net/wireless/mac80211_hwsim.c

index 60610c2a84848a0ee3ab865d66344102c0aa46e6..feddf4045a8ca6115fb74412acbe0e70eab6b183 100644 (file)
@@ -663,7 +663,7 @@ struct mac80211_hwsim_data {
        bool ps_poll_pending;
        struct dentry *debugfs;
 
-       atomic64_t pending_cookie;
+       atomic_t pending_cookie;
        struct sk_buff_head pending;    /* packets pending */
        /*
         * Only radios in the same group can communicate together (the
@@ -1270,7 +1270,7 @@ static void mac80211_hwsim_tx_frame_nl(struct ieee80211_hw *hw,
        int i;
        struct hwsim_tx_rate tx_attempts[IEEE80211_TX_MAX_RATES];
        struct hwsim_tx_rate_flag tx_attempts_flags[IEEE80211_TX_MAX_RATES];
-       u64 cookie;
+       uintptr_t cookie;
 
        if (data->ps != PS_DISABLED)
                hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PM);
@@ -1339,7 +1339,7 @@ static void mac80211_hwsim_tx_frame_nl(struct ieee80211_hw *hw,
                goto nla_put_failure;
 
        /* We create a cookie to identify this skb */
-       cookie = (u64)atomic64_inc_return(&data->pending_cookie);
+       cookie = atomic_inc_return(&data->pending_cookie);
        info->rate_driver_data[0] = (void *)cookie;
        if (nla_put_u64_64bit(skb, HWSIM_ATTR_COOKIE, cookie, HWSIM_ATTR_PAD))
                goto nla_put_failure;
@@ -3611,10 +3611,10 @@ static int hwsim_tx_info_frame_received_nl(struct sk_buff *skb_2,
        /* look for the skb matching the cookie passed back from user */
        spin_lock_irqsave(&data2->pending.lock, flags);
        skb_queue_walk_safe(&data2->pending, skb, tmp) {
-               u64 skb_cookie;
+               uintptr_t skb_cookie;
 
                txi = IEEE80211_SKB_CB(skb);
-               skb_cookie = (u64)(uintptr_t)txi->rate_driver_data[0];
+               skb_cookie = (uintptr_t)txi->rate_driver_data[0];
 
                if (skb_cookie == ret_skb_cookie) {
                        __skb_unlink(skb, &data2->pending);