From 02d7d89f816951e0862147d751b1150d67aaebdd Mon Sep 17 00:00:00 2001 From: Wang Weiyang Date: Wed, 23 Nov 2022 17:51:47 +0800 Subject: [PATCH] rapidio: fix possible UAF when kfifo_alloc() fails If kfifo_alloc() fails in mport_cdev_open(), goto err_fifo and just free priv. But priv is still in the chdev->file_list, then list traversal may cause UAF. This fixes the following smatch warning: drivers/rapidio/devices/rio_mport_cdev.c:1930 mport_cdev_open() warn: '&priv->list' not removed from list Link: https://lkml.kernel.org/r/20221123095147.52408-1-wangweiyang2@huawei.com Fixes: e8de370188d0 ("rapidio: add mport char device driver") Signed-off-by: Wang Weiyang Cc: Alexandre Bounine Cc: Dan Carpenter Cc: Jakob Koschel Cc: John Hubbard Cc: Matt Porter Cc: Yang Yingliang Signed-off-by: Andrew Morton --- drivers/rapidio/devices/rio_mport_cdev.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/rapidio/devices/rio_mport_cdev.c b/drivers/rapidio/devices/rio_mport_cdev.c index 3cc83997a1f8..fecf523f36d8 100644 --- a/drivers/rapidio/devices/rio_mport_cdev.c +++ b/drivers/rapidio/devices/rio_mport_cdev.c @@ -1904,10 +1904,6 @@ static int mport_cdev_open(struct inode *inode, struct file *filp) priv->md = chdev; - mutex_lock(&chdev->file_mutex); - list_add_tail(&priv->list, &chdev->file_list); - mutex_unlock(&chdev->file_mutex); - INIT_LIST_HEAD(&priv->db_filters); INIT_LIST_HEAD(&priv->pw_filters); spin_lock_init(&priv->fifo_lock); @@ -1926,6 +1922,9 @@ static int mport_cdev_open(struct inode *inode, struct file *filp) spin_lock_init(&priv->req_lock); mutex_init(&priv->dma_lock); #endif + mutex_lock(&chdev->file_mutex); + list_add_tail(&priv->list, &chdev->file_list); + mutex_unlock(&chdev->file_mutex); filp->private_data = priv; goto out;