Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux

wifi: rtl8xxxu: Fix memory leaks with RTL8723BU, RTL8192EU

The wifi + bluetooth combo chip RTL8723BU can leak memory (especially?)
when it's connected to a bluetooth audio device. The busy bluetooth
traffic generates lots of C2H (card to host) messages, which are not
freed correctly.

To fix this, move the dev_kfree_skb() call in rtl8xxxu_c2hcmd_callback()
inside the loop where skb_dequeue() is called.

The RTL8192EU leaks memory because the C2H messages are added to the
queue and left there forever. (This was fine in the past because it
probably wasn't sending any C2H messages until commit e542e66b7c2e
("wifi: rtl8xxxu: gen2: Turn on the rate control"). Since that commit
it sends a C2H message when the TX rate changes.)

To fix this, delete the check for rf_paths > 1 and the goto. Let the
function process the C2H messages from RTL8192EU like the ones from
the other chips.

Theoretically the RTL8188FU could also leak like RTL8723BU, but it
most likely doesn't send C2H messages frequently enough.

This change was tested with RTL8723BU by Erhard F. I tested it with
RTL8188FU and RTL8192EU.

Reported-by: Erhard F. <erhard_f@mailbox.org>
Tested-by: Erhard F. <erhard_f@mailbox.org>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215197
Fixes: e542e66b7c2e ("rtl8xxxu: add bluetooth co-existence support for single antenna")
Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
Reviewed-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/03b099c1-c671-d252-36f4-57b70d721f9d@gmail.com

authored by

Bitterblue Smith and committed by
Kalle Valo
b39f662c a3edb201

+2 -6
+2 -6
drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
··· 5702 5702 btcoex = &priv->bt_coex; 5703 5703 rarpt = &priv->ra_report; 5704 5704 5705 - if (priv->rf_paths > 1) 5706 - goto out; 5707 - 5708 5705 while (!skb_queue_empty(&priv->c2hcmd_queue)) { 5709 5706 skb = skb_dequeue(&priv->c2hcmd_queue); 5710 5707 ··· 5734 5737 default: 5735 5738 break; 5736 5739 } 5737 - } 5738 5740 5739 - out: 5740 - dev_kfree_skb(skb); 5741 + dev_kfree_skb(skb); 5742 + } 5741 5743 } 5742 5744 5743 5745 static void rtl8723bu_handle_c2h(struct rtl8xxxu_priv *priv,