This is a note to let you know that I've just added the patch titled
rapidio: fix possible UAF when kfifo_alloc() fails
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
rapidio-fix-possible-uaf-when-kfifo_alloc-fails.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 05be36f4b5d654ce315781375159ab80b7ec6329
Author: Wang Weiyang <wangweiyang2@xxxxxxxxxx>
Date: Wed Nov 23 17:51:47 2022 +0800
rapidio: fix possible UAF when kfifo_alloc() fails
[ 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>
diff --git a/drivers/rapidio/devices/rio_mport_cdev.c b/drivers/rapidio/devices/rio_mport_cdev.c
index 51440668ee79..8a420dfd5ee1 100644
--- a/drivers/rapidio/devices/rio_mport_cdev.c
+++ b/drivers/rapidio/devices/rio_mport_cdev.c
@@ -1907,10 +1907,6 @@ 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);
@@ -1929,6 +1925,9 @@ 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;
