input: fix touchevent race condition

Gary-Hobson · xiaoxiang781216 · commit 9694760eb8cd · 2024-08-23T08:52:23.000+08:00
In touch_event, circbuf is operated, and there is a lack of protection here.

Signed-off-by: yinshengkai &lt;yinshengkai@xiaomi.com&gt;
diff --git a/drivers/input/touchscreen_upper.c b/drivers/input/touchscreen_upper.c
@@ -375,6 +375,7 @@ static void touch_event_notify(FAR struct touch_openpriv_s  *openpriv,
 {
   int semcount;
 
+  nxmutex_lock(&openpriv->lock);
   circbuf_overwrite(&openpriv->circbuf, sample,
                     SIZEOF_TOUCH_SAMPLE_S(sample->npoints));
 
@@ -385,6 +386,7 @@ static void touch_event_notify(FAR struct touch_openpriv_s  *openpriv,
     }
 
   poll_notify(&openpriv->fds, 1, POLLIN);
+  nxmutex_unlock(&openpriv->lock);
 }
 
 /****************************************************************************

Original file line number	Diff line number	Diff line change
`@@ -375,6 +375,7 @@ static void touch_event_notify(FAR struct touch_openpriv_s *openpriv,`
`375`	`375`	`{`
`376`	`376`	`int semcount;`
`377`	`377`
	`378`	`+ nxmutex_lock(&openpriv->lock);`
`378`	`379`	`circbuf_overwrite(&openpriv->circbuf, sample,`
`379`	`380`	`SIZEOF_TOUCH_SAMPLE_S(sample->npoints));`
`380`	`381`
`@@ -385,6 +386,7 @@ static void touch_event_notify(FAR struct touch_openpriv_s *openpriv,`
`385`	`386`	`}`
`386`	`387`
`387`	`388`	`poll_notify(&openpriv->fds, 1, POLLIN);`
	`389`	`+ nxmutex_unlock(&openpriv->lock);`
`388`	`390`	`}`
`389`	`391`
`390`	`392`	`/****************************************************************************`