[PATCH 44/52] CRED: Pass credentials through the follow_link() inodeop
From: David Howells
Date: Fri Oct 12 2007 - 12:28:48 EST
Pass credentials through the follow_link() inode operation.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---
fs/afs/mntpt.c | 6 ++++--
fs/autofs4/root.c | 6 ++++--
fs/autofs4/symlink.c | 3 ++-
fs/ext3/symlink.c | 3 ++-
fs/namei.c | 9 ++++++---
fs/nfs/namespace.c | 5 +++--
fs/nfs/symlink.c | 4 ++--
fs/proc/base.c | 6 ++++--
fs/proc/generic.c | 3 ++-
fs/proc/proc_net.c | 3 ++-
fs/sysfs/dir.c | 2 +-
fs/sysfs/symlink.c | 3 ++-
include/linux/fs.h | 6 ++++--
include/linux/sysfs.h | 6 ++++--
mm/shmem.c | 7 +++++--
15 files changed, 47 insertions(+), 25 deletions(-)
diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c
index 21a04c0..864255e 100644
--- a/fs/afs/mntpt.c
+++ b/fs/afs/mntpt.c
@@ -26,7 +26,8 @@ static struct dentry *afs_mntpt_lookup(struct inode *dir,
struct nameidata *nd,
struct cred *cred);
static int afs_mntpt_open(struct inode *inode, struct file *file);
-static void *afs_mntpt_follow_link(struct dentry *dentry, struct nameidata *nd);
+static void *afs_mntpt_follow_link(struct dentry *dentry, struct nameidata *nd,
+ struct cred *cred);
static void afs_mntpt_expiry_timed_out(struct work_struct *work);
const struct file_operations afs_mntpt_file_operations = {
@@ -212,7 +213,8 @@ error:
/*
* follow a link from a mountpoint directory, thus causing it to be mounted
*/
-static void *afs_mntpt_follow_link(struct dentry *dentry, struct nameidata *nd)
+static void *afs_mntpt_follow_link(struct dentry *dentry, struct nameidata *nd,
+ struct cred *cred)
{
struct vfsmount *newmnt;
int err;
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index fd22c05..5ee7e2d 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -31,7 +31,8 @@ static int autofs4_dir_readdir(struct file * filp, void * dirent, filldir_t fill
static int autofs4_root_readdir(struct file * filp, void * dirent, filldir_t filldir);
static struct dentry *autofs4_lookup(struct inode *,struct dentry *,
struct nameidata *, struct cred *);
-static void *autofs4_follow_link(struct dentry *, struct nameidata *);
+static void *autofs4_follow_link(struct dentry *, struct nameidata *,
+ struct cred *);
const struct file_operations autofs4_root_operations = {
.open = dcache_dir_open,
@@ -325,7 +326,8 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags)
}
/* For autofs direct mounts the follow link triggers the mount */
-static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
+static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd,
+ struct cred *cred)
{
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
diff --git a/fs/autofs4/symlink.c b/fs/autofs4/symlink.c
index b4ea829..767d760 100644
--- a/fs/autofs4/symlink.c
+++ b/fs/autofs4/symlink.c
@@ -12,7 +12,8 @@
#include "autofs_i.h"
-static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
+static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd,
+ struct cred *cred)
{
struct autofs_info *ino = autofs4_dentry_ino(dentry);
nd_set_link(nd, (char *)ino->u.symlink);
diff --git a/fs/ext3/symlink.c b/fs/ext3/symlink.c
index ff7b4cc..b56a509 100644
--- a/fs/ext3/symlink.c
+++ b/fs/ext3/symlink.c
@@ -23,7 +23,8 @@
#include <linux/namei.h>
#include "xattr.h"
-static void * ext3_follow_link(struct dentry *dentry, struct nameidata *nd)
+static void * ext3_follow_link(struct dentry *dentry, struct nameidata *nd,
+ struct cred *cred)
{
struct ext3_inode_info *ei = EXT3_I(dentry->d_inode);
nd_set_link(nd, (char*)ei->i_data);
diff --git a/fs/namei.c b/fs/namei.c
index 1703fd0..d77e045 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -595,6 +595,7 @@ static inline void path_to_nameidata(struct path *path, struct nameidata *nd)
static __always_inline int __do_follow_link(struct path *path, struct nameidata *nd)
{
+ struct cred *cred = current->cred;
int error;
void *cookie;
struct dentry *dentry = path->dentry;
@@ -607,7 +608,7 @@ static __always_inline int __do_follow_link(struct path *path, struct nameidata
dget(dentry);
}
mntget(path->mnt);
- cookie = dentry->d_inode->i_op->follow_link(dentry, nd);
+ cookie = dentry->d_inode->i_op->follow_link(dentry, nd, cred);
error = PTR_ERR(cookie);
if (!IS_ERR(cookie)) {
char *s = nd_get_link(nd);
@@ -2682,11 +2683,12 @@ out:
*/
int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen)
{
+ struct cred *cred = current->cred;
struct nameidata nd;
void *cookie;
nd.depth = 0;
- cookie = dentry->d_inode->i_op->follow_link(dentry, &nd);
+ cookie = dentry->d_inode->i_op->follow_link(dentry, &nd, cred);
if (!IS_ERR(cookie)) {
int res = vfs_readlink(dentry, buffer, buflen, nd_get_link(&nd));
if (dentry->d_inode->i_op->put_link)
@@ -2725,7 +2727,8 @@ int page_readlink(struct dentry *dentry, char __user *buffer, int buflen)
return res;
}
-void *page_follow_link_light(struct dentry *dentry, struct nameidata *nd)
+void *page_follow_link_light(struct dentry *dentry, struct nameidata *nd,
+ struct cred *cred)
{
struct page *page = NULL;
nd_set_link(nd, page_getlink(dentry, &page));
diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index b8d3576..72f305f 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -85,6 +85,7 @@ Elong:
* nfs_follow_mountpoint - handle crossing a mountpoint on the server
* @dentry - dentry of mountpoint
* @nd - nameidata info
+ * @acred - the credentials to use
*
* When we encounter a mountpoint on the server, we want to set up
* a mountpoint on the client too, to prevent inode numbers from
@@ -94,9 +95,9 @@ Elong:
* situation, and that different filesystems may want to use
* different security flavours.
*/
-static void * nfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd)
+static void * nfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd,
+ struct cred *acred)
{
- struct cred *acred = current->cred;
struct vfsmount *mnt;
struct nfs_server *server = NFS_SERVER(dentry->d_inode);
struct dentry *parent;
diff --git a/fs/nfs/symlink.c b/fs/nfs/symlink.c
index cd1df31..1186339 100644
--- a/fs/nfs/symlink.c
+++ b/fs/nfs/symlink.c
@@ -53,10 +53,10 @@ error:
return -EIO;
}
-static void *nfs_follow_link(struct dentry *dentry, struct nameidata *nd)
+static void *nfs_follow_link(struct dentry *dentry, struct nameidata *nd,
+ struct cred *acred)
{
struct inode *inode = dentry->d_inode;
- struct cred *acred = current->cred;
struct page *page;
void *err;
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 9262681..d26cf33 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -933,7 +933,8 @@ static const struct file_operations proc_pid_sched_operations = {
#endif
-static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
+static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd,
+ struct cred *cred)
{
struct inode *inode = dentry->d_inode;
int error = -EACCES;
@@ -1896,7 +1897,8 @@ static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
return vfs_readlink(dentry,buffer,buflen,tmp);
}
-static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
+static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd,
+ struct cred *cred)
{
char tmp[PROC_NUMBUF];
sprintf(tmp, "%d", current->tgid);
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index ef5fb3a..ea67aac 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -353,7 +353,8 @@ static void release_inode_number(unsigned int inum)
spin_unlock(&proc_inum_lock);
}
-static void *proc_follow_link(struct dentry *dentry, struct nameidata *nd)
+static void *proc_follow_link(struct dentry *dentry, struct nameidata *nd,
+ struct cred *cred)
{
nd_set_link(nd, PDE(dentry->d_inode)->data);
return NULL;
diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c
index a1a2fa9..7062644 100644
--- a/fs/proc/proc_net.c
+++ b/fs/proc/proc_net.c
@@ -84,7 +84,8 @@ out_de_put:
goto out;
}
-static void *proc_net_follow_link(struct dentry *parent, struct nameidata *nd)
+static void *proc_net_follow_link(struct dentry *parent, struct nameidata *nd,
+ struct cred *cred)
{
struct net *net = current->nsproxy->net_ns;
struct dentry *shadow;
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 6a4bfb0..96e2fd8 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -1199,7 +1199,7 @@ static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
*/
int sysfs_make_shadowed_dir(struct kobject *kobj,
- void * (*follow_link)(struct dentry *, struct nameidata *))
+ sysfs_follow_link_t follow_link)
{
struct dentry *dentry;
struct inode *inode;
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index 4ce687f..34e0e08 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -158,7 +158,8 @@ static int sysfs_getlink(struct dentry *dentry, char * path)
return error;
}
-static void *sysfs_follow_link(struct dentry *dentry, struct nameidata *nd)
+static void *sysfs_follow_link(struct dentry *dentry, struct nameidata *nd,
+ struct cred *cred)
{
int error = -ENOMEM;
unsigned long page = get_zeroed_page(GFP_KERNEL);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2fec09a..9e7ac7c 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1151,7 +1151,8 @@ struct inode_operations {
struct inode *, struct dentry *,
struct cred *);
int (*readlink) (struct dentry *, char __user *,int);
- void * (*follow_link) (struct dentry *, struct nameidata *);
+ void * (*follow_link) (struct dentry *, struct nameidata *,
+ struct cred *);
void (*put_link) (struct dentry *, struct nameidata *, void *);
void (*truncate) (struct inode *, struct cred *);
int (*permission) (struct inode *, int, struct nameidata *,
@@ -1767,7 +1768,8 @@ extern const struct file_operations generic_ro_fops;
extern int vfs_readlink(struct dentry *, char __user *, int, const char *);
extern int vfs_follow_link(struct nameidata *, const char *);
extern int page_readlink(struct dentry *, char __user *, int);
-extern void *page_follow_link_light(struct dentry *, struct nameidata *);
+extern void *page_follow_link_light(struct dentry *, struct nameidata *,
+ struct cred *);
extern void page_put_link(struct dentry *, struct nameidata *, void *);
extern int __page_symlink(struct inode *inode, const char *symname, int len,
gfp_t gfp_mask);
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index be8228e..d84c82b 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -20,6 +20,7 @@ struct module;
struct nameidata;
struct dentry;
struct sysfs_dirent;
+struct cred;
/* FIXME
* The *owner field is no longer used, but leave around
@@ -138,9 +139,10 @@ void sysfs_remove_file_from_group(struct kobject *kobj,
void sysfs_notify(struct kobject * k, char *dir, char *attr);
-
+typedef void *(*sysfs_follow_link_t)(struct dentry *, struct nameidata *,
+ struct cred *);
extern int sysfs_make_shadowed_dir(struct kobject *kobj,
- void * (*follow_link)(struct dentry *, struct nameidata *));
+ sysfs_follow_link_t follow_link);
extern struct sysfs_dirent *sysfs_create_shadow_dir(struct kobject *kobj);
extern void sysfs_remove_shadow_dir(struct sysfs_dirent *shadow_sd);
diff --git a/mm/shmem.c b/mm/shmem.c
index 432f023..a3c2007 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1912,13 +1912,16 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry,
return 0;
}
-static void *shmem_follow_link_inline(struct dentry *dentry, struct nameidata *nd)
+static void *shmem_follow_link_inline(struct dentry *dentry,
+ struct nameidata *nd,
+ struct cred *cred)
{
nd_set_link(nd, (char *)SHMEM_I(dentry->d_inode));
return NULL;
}
-static void *shmem_follow_link(struct dentry *dentry, struct nameidata *nd)
+static void *shmem_follow_link(struct dentry *dentry, struct nameidata *nd,
+ struct cred *cred)
{
struct page *page = NULL;
int res = shmem_getpage(dentry->d_inode, 0, &page, SGP_READ, NULL);
-
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