[patch added to 3.12-stable] cifs: Check for existing directory when opening file with O_CREAT
From: Jiri Slaby <hidden>
Date: 2016-08-18 12:50:22
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
From: Sachin Prabhu <redacted> This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== 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 <redacted> Signed-off-by: Steve French <redacted> Reported-by: Xiaoli Feng <redacted> Signed-off-by: Jiri Slaby <redacted> --- 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 f039c23d003d..7347f1678fa7 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
--
2.9.3