From 5bccda0ebc7c0331b81ac47d39e4b920b198b2cd Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Thu, 23 Feb 2012 09:37:45 -0500 Subject: [PATCH] cifs: fix dentry refcount leak when opening a FIFO on lookup The cifs code will attempt to open files on lookup under certain circumstances. What happens though if we find that the file we opened was actually a FIFO or other special file? Currently, the open filehandle just ends up being leaked leading to a dentry refcount mismatch and oops on umount. Fix this by having the code close the filehandle on the server if it turns out not to be a regular file. While we're at it, change this spaghetti if statement into a switch too. Cc: stable@vger.kernel.org Reported-by: CAI Qian Tested-by: CAI Qian Reviewed-by: Shirish Pargaonkar Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/dir.c | 20 ++++++++++++++++++-- 1 files changed, 18 insertions(+), 2 deletions(-) diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c index 63a196b..bc7e244 100644 --- a/fs/cifs/dir.c +++ b/fs/cifs/dir.c @@ -584,10 +584,26 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, * If either that or op not supported returned, follow * the normal lookup. */ - if ((rc == 0) || (rc == -ENOENT)) + switch (rc) { + case 0: + /* + * The server may allow us to open things like + * FIFOs, but the client isn't set up to deal + * with that. If it's not a regular file, just + * close it and proceed as if it were a normal + * lookup. + */ + if (newInode && !S_ISREG(newInode->i_mode)) { + CIFSSMBClose(xid, pTcon, fileHandle); + break; + } + case -ENOENT: posix_open = true; - else if ((rc == -EINVAL) || (rc != -EOPNOTSUPP)) + case -EOPNOTSUPP: + break; + default: pTcon->broken_posix_open = true; + } } if (!posix_open) rc = cifs_get_inode_info_unix(&newInode, full_path, -- 1.7.0.4