[PATCH] wifi: libertas_tf: fix UAF in lbtf_free_adapter()

[Jiangshan Yi]

lbtf_free_adapter() calls lbtf_free_cmd_buffer() to free the command
buffers before calling timer_delete_sync() to wait for the command
timer callback.  If the timer callback (command_timer_fn) is already
running when lbtf_free_cmd_buffer() frees the command array, the
callback dereferences priv->cur_cmd->cmdbuf which points to freed
memory.

Swap the order so that timer_delete_sync() runs first, ensuring any
in-flight callback has completed before the command buffers are freed.

Fixes: 06b16ae53192 ("libertas_tf: main.c, data paths and mac80211 handlers")
Cc: stable at vger.kernel.org
Signed-off-by: Jiangshan Yi <yijiangshan at kylinos.cn>
---
 drivers/net/wireless/marvell/libertas_tf/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/marvell/libertas_tf/main.c b/drivers/net/wireless/marvell/libertas_tf/main.c
index 42be6fa22f9c..411f075b6186 100644
--- a/drivers/net/wireless/marvell/libertas_tf/main.c
+++ b/drivers/net/wireless/marvell/libertas_tf/main.c
@@ -173,8 +173,8 @@ static int lbtf_init_adapter(struct lbtf_private *priv)
 static void lbtf_free_adapter(struct lbtf_private *priv)
 {
 	lbtf_deb_enter(LBTF_DEB_MAIN);
-	lbtf_free_cmd_buffer(priv);
 	timer_delete_sync(&priv->command_timer);
+	lbtf_free_cmd_buffer(priv);
 	lbtf_deb_leave(LBTF_DEB_MAIN);
 }
 
-- 
2.25.1