Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 3.14 11/46] cifs: Check for existing directory when opening file with O_CREAT | Date | Thu, 18 Aug 2016 15:54:33 +0200 |
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3.14-stable review patch. If anyone has any objections, please let me know.
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From: Sachin Prabhu <sprabhu@redhat.com>
commit 8d9535b6efd86e6c07da59f97e68f44efb7fe080 upstream.
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 <sprabhu@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com> Reported-by: Xiaoli Feng <xifeng@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/cifs/dir.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-)
--- a/fs/cifs/dir.c +++ b/fs/cifs/dir.c @@ -229,6 +229,13 @@ cifs_do_create(struct inode *inode, stru 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
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