From: Jeongik Cha <jeongik@xxxxxxxxxx> commit 4ee186fa7e40ae06ebbfbad77e249e3746e14114 upstream. A pending packet uses a cookie as an unique key, but it can be duplicated because it didn't use atomic operators. And also, a pending packet can be null in hwsim_tx_info_frame_received_nl due to race condition with mac80211_hwsim_stop. For this, * Use an atomic type and operator for a cookie * Add a lock around the loop for pending packets Signed-off-by: Jeongik Cha <jeongik@xxxxxxxxxx> Link: https://lore.kernel.org/r/20220704084354.3556326-1-jeongik@xxxxxxxxxx Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/wireless/mac80211_hwsim.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -527,7 +527,7 @@ struct mac80211_hwsim_data { bool ps_poll_pending; struct dentry *debugfs; - uintptr_t pending_cookie; + atomic64_t pending_cookie; struct sk_buff_head pending; /* packets pending */ /* * Only radios in the same group can communicate together (the @@ -1044,7 +1044,7 @@ static void mac80211_hwsim_tx_frame_nl(s int i; struct hwsim_tx_rate tx_attempts[IEEE80211_TX_MAX_RATES]; struct hwsim_tx_rate_flag tx_attempts_flags[IEEE80211_TX_MAX_RATES]; - uintptr_t cookie; + u64 cookie; if (data->ps != PS_DISABLED) hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PM); @@ -1113,8 +1113,7 @@ static void mac80211_hwsim_tx_frame_nl(s goto nla_put_failure; /* We create a cookie to identify this skb */ - data->pending_cookie++; - cookie = data->pending_cookie; + cookie = (u64)atomic64_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; @@ -3260,6 +3259,7 @@ static int hwsim_tx_info_frame_received_ const u8 *src; unsigned int hwsim_flags; int i; + unsigned long flags; bool found = false; if (!info->attrs[HWSIM_ATTR_ADDR_TRANSMITTER] || @@ -3284,18 +3284,20 @@ static int hwsim_tx_info_frame_received_ goto out; /* 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; txi = IEEE80211_SKB_CB(skb); - skb_cookie = (u64)(uintptr_t)txi->rate_driver_data[0]; + skb_cookie = (u64)txi->rate_driver_data[0]; if (skb_cookie == ret_skb_cookie) { - skb_unlink(skb, &data2->pending); + __skb_unlink(skb, &data2->pending); found = true; break; } } + spin_unlock_irqrestore(&data2->pending.lock, flags); /* not found */ if (!found)
