From: Wang Weiyang <wangweiyang2@xxxxxxxxxx> [ Upstream commit 02d7d89f816951e0862147d751b1150d67aaebdd ] 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@xxxxxxxxxx Fixes: e8de370188d0 ("rapidio: add mport char device driver") Signed-off-by: Wang Weiyang <wangweiyang2@xxxxxxxxxx> Cc: Alexandre Bounine <alex.bou9@xxxxxxxxx> Cc: Dan Carpenter <error27@xxxxxxxxx> Cc: Jakob Koschel <jakobkoschel@xxxxxxxxx> Cc: John Hubbard <jhubbard@xxxxxxxxxx> Cc: Matt Porter <mporter@xxxxxxxxxxxxxxxxxxx> Cc: Yang Yingliang <yangyingliang@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 c0597b6d75ef..381354ef0959 100644 --- a/drivers/rapidio/devices/rio_mport_cdev.c +++ b/drivers/rapidio/devices/rio_mport_cdev.c @@ -1964,10 +1964,6 @@ 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); @@ -1987,6 +1983,9 @@ 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; -- 2.35.1
