From: Jeff Layton <jlay...@redhat.com>
-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git
If you see a problem with using this for longterm, please comment.
-------------------
commit 5bccda0ebc7c0331b81ac47d39e4b920b198b2cd upstream.
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.
Reported-by: CAI Qian <caiq...@redhat.com>
Tested-by: CAI Qian <caiq...@redhat.com>
Reviewed-by: Shirish Pargaonkar <shirishpargaon...@gmail.com>
Signed-off-by: Jeff Layton <jlay...@redhat.com>
Signed-off-by: Steve French <smfre...@gmail.com>
Signed-off-by: Paul Gortmaker <paul.gortma...@windriver.com>
---
fs/cifs/dir.c | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index ff3d891..fc79b95 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -692,10 +692,26 @@ 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,
--
1.7.12.rc2
--
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