From 454994cfa9e4c18b6df9f78b60db8eadc20a6c25 Mon Sep 17 00:00:00 2001 From: Fedor Pchelkin Date: Tue, 25 Apr 2023 22:26:07 +0300 Subject: wifi: ath9k: protect WMI command response buffer replacement with a lock MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If ath9k_wmi_cmd() has exited with a timeout, it is possible that during next ath9k_wmi_cmd() call the wmi_rsp callback for previous wmi command writes to new wmi->cmd_rsp_buf and makes a completion. This results in an invalid ath9k_wmi_cmd() return value. Move the replacement of WMI command response buffer and length under wmi_lock. Note that last_seq_id value is updated there, too. Thus, the buffer cannot be written to by a belated wmi_rsp callback because that path is properly rejected by the last_seq_id check. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: fb9987d0f748 ("ath9k_htc: Support for AR9271 chipset.") Signed-off-by: Fedor Pchelkin Acked-by: Toke Høiland-Jørgensen Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20230425192607.18015-2-pchelkin@ispras.ru --- drivers/net/wireless/ath/ath9k/wmi.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (limited to 'drivers/net/wireless/ath/ath9k/wmi.c') diff --git a/drivers/net/wireless/ath/ath9k/wmi.c b/drivers/net/wireless/ath/ath9k/wmi.c index 04f363cb90fe..1476b42b52a9 100644 --- a/drivers/net/wireless/ath/ath9k/wmi.c +++ b/drivers/net/wireless/ath/ath9k/wmi.c @@ -283,7 +283,8 @@ int ath9k_wmi_connect(struct htc_target *htc, struct wmi *wmi, static int ath9k_wmi_cmd_issue(struct wmi *wmi, struct sk_buff *skb, - enum wmi_cmd_id cmd, u16 len) + enum wmi_cmd_id cmd, u16 len, + u8 *rsp_buf, u32 rsp_len) { struct wmi_cmd_hdr *hdr; unsigned long flags; @@ -293,6 +294,11 @@ static int ath9k_wmi_cmd_issue(struct wmi *wmi, hdr->seq_no = cpu_to_be16(++wmi->tx_seq_id); spin_lock_irqsave(&wmi->wmi_lock, flags); + + /* record the rsp buffer and length */ + wmi->cmd_rsp_buf = rsp_buf; + wmi->cmd_rsp_len = rsp_len; + wmi->last_seq_id = wmi->tx_seq_id; spin_unlock_irqrestore(&wmi->wmi_lock, flags); @@ -333,11 +339,7 @@ int ath9k_wmi_cmd(struct wmi *wmi, enum wmi_cmd_id cmd_id, goto out; } - /* record the rsp buffer and length */ - wmi->cmd_rsp_buf = rsp_buf; - wmi->cmd_rsp_len = rsp_len; - - ret = ath9k_wmi_cmd_issue(wmi, skb, cmd_id, cmd_len); + ret = ath9k_wmi_cmd_issue(wmi, skb, cmd_id, cmd_len, rsp_buf, rsp_len); if (ret) goto out; -- cgit v1.2.3