[PATCH 1/1] fix d_revalidate oopsen on NFS exports

From: Chris Dunlop
Date: Mon Nov 21 2011 - 02:45:27 EST


can't blindly check nd->flags in ->d_revalidate()

Has been previously done for various other file systems:

git blame -L 1768,+1 fs/proc/base.c
34286d66 (Nick Piggin 2011-01-07 17:49:57 +1100 1768) if (nd && nd->flags & LOOKUP_RCU)
git blame -L 645,+1 fs/cifs/dir.c
3ca30d40 (Pavel Shilovsky 2011-07-25 17:59:10 +0400 645) if (nd && (nd->flags & LOOKUP_RCU))
git blame -L 46,+1 fs/fat/namei_vfat.c
9177ada9 (Al Viro 2011-03-10 03:45:49 -0500 46) if (nd && nd->flags & LOOKUP_RCU)
git blame -L 57,+1 fs/fat/namei_vfat.c
9177ada9 (Al Viro 2011-03-10 03:45:49 -0500 57) if (nd && nd->flags & LOOKUP_RCU)
git blame -L 177,+1 fs/fuse/dir.c
d2433905 (Miklos Szeredi 2011-05-10 17:35:58 +0200 177) if (nd && (nd->flags & LOOKUP_RCU))
git blame -L 1036,+1 fs/ceph/dir.c
0eb980e3 (Al Viro 2011-03-10 03:44:05 -0500 1036) if (nd && nd->flags & LOOKUP_RCU)
git blame -L 47,+1 fs/gfs2/dentry.c
53fe9241 (Al Viro 2011-03-10 03:44:48 -0500 47) if (nd && nd->flags & LOOKUP_RCU)
git blame -L 53,+1 fs/ecryptfs/dentry.c
70b89021 (Tyler Hicks 2011-02-17 17:35:20 -0600 53) if (nd && nd->flags & LOOKUP_RCU)
git blame -L 59,+1 fs/ocfs2/dcache.c
4714e637 (Al Viro 2011-03-10 03:45:07 -0500 59) if (nd && nd->flags & LOOKUP_RCU)

Signed-off-by: Chris Dunlop <chris@xxxxxxxxxxxx>
---
fs/9p/vfs_dentry.c | 2 +-
fs/afs/dir.c | 2 +-
fs/coda/dir.c | 2 +-
fs/hfs/sysdep.c | 2 +-
fs/jfs/namei.c | 3 +++
fs/ncpfs/dir.c | 2 +-
fs/nfs/dir.c | 2 +-
fs/proc/proc_sysctl.c | 2 +-
fs/sysfs/dir.c | 2 +-
9 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/fs/9p/vfs_dentry.c b/fs/9p/vfs_dentry.c
index e022890..2be4b91 100644
--- a/fs/9p/vfs_dentry.c
+++ b/fs/9p/vfs_dentry.c
@@ -106,7 +106,7 @@ static int v9fs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
struct inode *inode;
struct v9fs_inode *v9inode;

- if (nd->flags & LOOKUP_RCU)
+ if (nd && nd->flags & LOOKUP_RCU)
return -ECHILD;

inode = dentry->d_inode;
diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index 1b0b195..4112d68 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -607,7 +607,7 @@ static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
void *dir_version;
int ret;

- if (nd->flags & LOOKUP_RCU)
+ if (nd && nd->flags & LOOKUP_RCU)
return -ECHILD;

vnode = AFS_FS_I(dentry->d_inode);
diff --git a/fs/coda/dir.c b/fs/coda/dir.c
index 28e7e13..0cf4a68 100644
--- a/fs/coda/dir.c
+++ b/fs/coda/dir.c
@@ -544,7 +544,7 @@ static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd)
struct inode *inode;
struct coda_inode_info *cii;

- if (nd->flags & LOOKUP_RCU)
+ if (nd && nd->flags & LOOKUP_RCU)
return -ECHILD;

inode = de->d_inode;
diff --git a/fs/hfs/sysdep.c b/fs/hfs/sysdep.c
index 19cf291..1127ea3 100644
--- a/fs/hfs/sysdep.c
+++ b/fs/hfs/sysdep.c
@@ -18,7 +18,7 @@ static int hfs_revalidate_dentry(struct dentry *dentry, struct nameidata *nd)
struct inode *inode;
int diff;

- if (nd->flags & LOOKUP_RCU)
+ if (nd && nd->flags & LOOKUP_RCU)
return -ECHILD;

inode = dentry->d_inode;
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index a112ad9..e3b65d6 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -1585,6 +1585,9 @@ out:

static int jfs_ci_revalidate(struct dentry *dentry, struct nameidata *nd)
{
+ if (nd && (nd->flags & LOOKUP_RCU))
+ return -ECHILD;
+
/*
* This is not negative dentry. Always valid.
*
diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index 9c51f62..1fb3de3 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -302,7 +302,7 @@ ncp_lookup_validate(struct dentry *dentry, struct nameidata *nd)
if (dentry == dentry->d_sb->s_root)
return 1;

- if (nd->flags & LOOKUP_RCU)
+ if (nd && nd->flags & LOOKUP_RCU)
return -ECHILD;

parent = dget_parent(dentry);
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index b238d95..88c0f6e 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1103,7 +1103,7 @@ static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
struct nfs_fattr *fattr = NULL;
int error;

- if (nd->flags & LOOKUP_RCU)
+ if (nd && nd->flags & LOOKUP_RCU)
return -ECHILD;

parent = dget_parent(dentry);
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index a6b6217..0437e4a 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -435,7 +435,7 @@ static const struct inode_operations proc_sys_dir_operations = {

static int proc_sys_revalidate(struct dentry *dentry, struct nameidata *nd)
{
- if (nd->flags & LOOKUP_RCU)
+ if (nd && nd->flags & LOOKUP_RCU)
return -ECHILD;
return !PROC_I(dentry->d_inode)->sysctl->unregistering;
}
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 7fdf6a7..8f36a13 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -261,7 +261,7 @@ static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd)
struct sysfs_dirent *sd;
int is_dir;

- if (nd->flags & LOOKUP_RCU)
+ if (nd && nd->flags & LOOKUP_RCU)
return -ECHILD;

sd = dentry->d_fsdata;
--
1.7.0.4

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