From 8d9535b6efd86e6c07da59f97e68f44efb7fe080 Mon Sep 17 00:00:00 2001 From: Sachin Prabhu Date: Thu, 7 Jul 2016 21:28:27 +0100 Subject: [PATCH] cifs: Check for existing directory when opening file with O_CREAT When opening a file with O_CREAT flag, check to see if the file opened is an existing directory. This prevents the directory from being opened which subsequently causes a crash when the close function for directories cifs_closedir() is called which frees up the file->private_data memory while the file is still listed on the open file list for the tcon. Signed-off-by: Sachin Prabhu Signed-off-by: Steve French CC: Stable Reported-by: Xiaoli Feng --- fs/cifs/dir.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c index c3eb998a99bd..5089e426371a 100644 --- a/fs/cifs/dir.c +++ b/fs/cifs/dir.c @@ -229,6 +229,13 @@ cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid, goto cifs_create_get_file_info; } + if (S_ISDIR(newinode->i_mode)) { + CIFSSMBClose(xid, tcon, fid->netfid); + iput(newinode); + rc = -EISDIR; + goto out; + } + if (!S_ISREG(newinode->i_mode)) { /* * The server may allow us to open things like @@ -399,10 +406,14 @@ cifs_create_set_dentry: if (rc != 0) { cifs_dbg(FYI, "Create worked, get_inode_info failed rc = %d\n", rc); - if (server->ops->close) - server->ops->close(xid, tcon, fid); - goto out; + goto out_err; } + + if (S_ISDIR(newinode->i_mode)) { + rc = -EISDIR; + goto out_err; + } + d_drop(direntry); d_add(direntry, newinode); @@ -410,6 +421,13 @@ out: kfree(buf); kfree(full_path); return rc; + +out_err: + if (server->ops->close) + server->ops->close(xid, tcon, fid); + if (newinode) + iput(newinode); + goto out; } int