From fe5c271e2878fb080f1b32fec5b4e3f7a6070152 Mon Sep 17 00:00:00 2001 From: Maya Erez Date: Thu, 28 Jan 2016 19:24:04 +0200 Subject: [PATCH] wil6210: protect synchronous wmi commands handling MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit In case there are multiple WMI commands with the same reply_id, the following scenario can occur: - Driver sends the first command to the device - The reply didn’t get on time and there is timeout - Reply_id, reply_buf and reply_size are set to 0 - Driver sends second wmi command with the same reply_id as the first - Driver sets wil->reply_id - Reply for the first wmi command arrives and handled by wmi_recv_cmd - As its ID fits the reply_id but the reply_buf is not set yet it is handled as a reply with event handler, and WARN_ON is printed This patch guarantee atomic setting of all the reply variables and prevents the above scenario. Signed-off-by: Maya Erez Signed-off-by: Kalle Valo --- drivers/net/wireless/ath/wil6210/wmi.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/ath/wil6210/wmi.c b/drivers/net/wireless/ath/wil6210/wmi.c index e1a6cb8..493e721 100644 --- a/drivers/net/wireless/ath/wil6210/wmi.c +++ b/drivers/net/wireless/ath/wil6210/wmi.c @@ -838,6 +838,7 @@ void wmi_recv_cmd(struct wil6210_priv *wil) struct wil6210_mbox_hdr_wmi *wmi = &evt->event.wmi; u16 id = le16_to_cpu(wmi->id); u32 tstamp = le32_to_cpu(wmi->timestamp); + spin_lock_irqsave(&wil->wmi_ev_lock, flags); if (wil->reply_id && wil->reply_id == id) { if (wil->reply_buf) { memcpy(wil->reply_buf, wmi, @@ -845,6 +846,7 @@ void wmi_recv_cmd(struct wil6210_priv *wil) immed_reply = true; } } + spin_unlock_irqrestore(&wil->wmi_ev_lock, flags); wil_dbg_wmi(wil, "WMI event 0x%04x MID %d @%d msec\n", id, wmi->mid, tstamp); @@ -888,13 +890,16 @@ int wmi_call(struct wil6210_priv *wil, u16 cmdid, void *buf, u16 len, mutex_lock(&wil->wmi_mutex); + spin_lock(&wil->wmi_ev_lock); + wil->reply_id = reply_id; + wil->reply_buf = reply; + wil->reply_size = reply_size; + spin_unlock(&wil->wmi_ev_lock); + rc = __wmi_send(wil, cmdid, buf, len); if (rc) goto out; - wil->reply_id = reply_id; - wil->reply_buf = reply; - wil->reply_size = reply_size; remain = wait_for_completion_timeout(&wil->wmi_call, msecs_to_jiffies(to_msec)); if (0 == remain) { @@ -907,10 +912,14 @@ int wmi_call(struct wil6210_priv *wil, u16 cmdid, void *buf, u16 len, cmdid, reply_id, to_msec - jiffies_to_msecs(remain)); } + +out: + spin_lock(&wil->wmi_ev_lock); wil->reply_id = 0; wil->reply_buf = NULL; wil->reply_size = 0; - out: + spin_unlock(&wil->wmi_ev_lock); + mutex_unlock(&wil->wmi_mutex); return rc; -- 2.7.4