lkml.org 
[lkml]   [2017]   [May]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.4 18/20] ext4/fscrypto: avoid RCU lookup in d_revalidate
Date
4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jaegeuk Kim <jaegeuk@kernel.org>

commit 03a8bb0e53d9562276045bdfcf2b5de2e4cff5a1 upstream.

As Al pointed, d_revalidate should return RCU lookup before using d_inode.
This was originally introduced by:
commit 34286d666230 ("fs: rcu-walk aware d_revalidate method").

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/ext4/crypto.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/fs/ext4/crypto.c
+++ b/fs/ext4/crypto.c
@@ -34,6 +34,7 @@
#include <linux/random.h>
#include <linux/scatterlist.h>
#include <linux/spinlock_types.h>
+#include <linux/namei.h>

#include "ext4_extents.h"
#include "xattr.h"
@@ -481,6 +482,9 @@ static int ext4_d_revalidate(struct dent
struct ext4_crypt_info *ci;
int dir_has_key, cached_with_key;

+ if (flags & LOOKUP_RCU)
+ return -ECHILD;
+
dir = dget_parent(dentry);
if (!ext4_encrypted_inode(d_inode(dir))) {
dput(dir);

\
 
 \ /
  Last update: 2017-05-05 20:39    [W:0.147 / U:0.160 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site