[3.13.y.z extended stable] Patch "__dentry_path() fixes" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    __dentry_path() fixes

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.1.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From c5e52d8ded9c4a956b6ce961c1fa52b96e2dae71 Mon Sep 17 00:00:00 2001
From: Al Viro <viro at zeniv.linux.org.uk>
Date: Sun, 26 Jan 2014 12:37:55 -0500
Subject: __dentry_path() fixes

commit f6500801522c61782d4990fa1ad96154cb397cd4 upstream.

* we need to save the starting point for restarts
* reject pathologically short buffers outright

Spotted-by: Denys Vlasenko <dvlasenk at redhat.com>
Spotted-by: Oleg Nesterov <oleg at redhat.com>
Signed-off-by: Al Viro <viro at zeniv.linux.org.uk>
Cc: Mikulas Patocka <mpatocka at redhat.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 fs/dcache.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index f7ad6d7..ca02c13 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -3116,19 +3116,22 @@ char *simple_dname(struct dentry *dentry, char *buffer, int buflen)
 /*
  * Write full pathname from the root of the filesystem into the buffer.
  */
-static char *__dentry_path(struct dentry *dentry, char *buf, int buflen)
+static char *__dentry_path(struct dentry *d, char *buf, int buflen)
 {
+	struct dentry *dentry;
 	char *end, *retval;
 	int len, seq = 0;
 	int error = 0;

+	if (buflen < 2)
+		goto Elong;
+
 	rcu_read_lock();
 restart:
+	dentry = d;
 	end = buf + buflen;
 	len = buflen;
 	prepend(&end, &len, "\0", 1);
-	if (buflen < 1)
-		goto Elong;
 	/* Get '/' right */
 	retval = end-1;
 	*retval = '/';
--
1.9.1