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authorAl Viro <viro@zeniv.linux.org.uk>2010-06-07 05:51:16 +0400
committerAl Viro <viro@zeniv.linux.org.uk>2010-08-10 00:48:12 +0400
commitd0352d3ed722b134dacc21836c1763e7e3523662 (patch)
tree030c031e5defb8c496f1b4766056c26e5460558a /fs/hostfs
parentc5322220eb91b9e56ac7b69eb690d9d20fac5725 (diff)
downloadlinux-d0352d3ed722b134dacc21836c1763e7e3523662.tar.xz
hostfs: sanitize symlinks
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/hostfs')
-rw-r--r--fs/hostfs/hostfs_kern.c61
1 files changed, 35 insertions, 26 deletions
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index 3841fb1ca5a2..10bb71b1548b 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -14,6 +14,7 @@
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/mount.h>
+#include <linux/namei.h>
#include "hostfs.h"
#include "init.h"
#include "kern.h"
@@ -48,7 +49,7 @@ static int append = 0;
static const struct inode_operations hostfs_iops;
static const struct inode_operations hostfs_dir_iops;
-static const struct address_space_operations hostfs_link_aops;
+static const struct inode_operations hostfs_link_iops;
#ifndef MODULE
static int __init hostfs_args(char *options, int *add)
@@ -471,8 +472,7 @@ static int read_name(struct inode *ino, char *name)
switch (st.mode & S_IFMT) {
case S_IFLNK:
- ino->i_op = &page_symlink_inode_operations;
- ino->i_mapping->a_ops = &hostfs_link_aops;
+ ino->i_op = &hostfs_link_iops;
break;
case S_IFDIR:
ino->i_op = &hostfs_dir_iops;
@@ -835,32 +835,41 @@ static const struct inode_operations hostfs_dir_iops = {
.setattr = hostfs_setattr,
};
-int hostfs_link_readpage(struct file *file, struct page *page)
-{
- char *buffer, *name;
- int err;
-
- buffer = kmap(page);
- name = inode_name(page->mapping->host);
- if (name == NULL)
- return -ENOMEM;
- err = hostfs_do_readlink(name, buffer, PAGE_CACHE_SIZE);
- kfree(name);
- if (err == PAGE_CACHE_SIZE)
- err = -E2BIG;
- else if (err > 0) {
- flush_dcache_page(page);
- SetPageUptodate(page);
- if (PageError(page)) ClearPageError(page);
- err = 0;
+static void *hostfs_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+ char *link = __getname();
+ if (link) {
+ char *path = dentry_name(dentry);
+ int err = -ENOMEM;
+ if (path) {
+ int err = hostfs_do_readlink(path, link, PATH_MAX);
+ if (err == PATH_MAX)
+ err = -E2BIG;
+ kfree(path);
+ }
+ if (err < 0) {
+ __putname(link);
+ link = ERR_PTR(err);
+ }
+ } else {
+ link = ERR_PTR(-ENOMEM);
}
- kunmap(page);
- unlock_page(page);
- return err;
+
+ nd_set_link(nd, link);
+ return NULL;
+}
+
+static void hostfs_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
+{
+ char *s = nd_get_link(nd);
+ if (!IS_ERR(s))
+ __putname(s);
}
-static const struct address_space_operations hostfs_link_aops = {
- .readpage = hostfs_link_readpage,
+static const struct inode_operations hostfs_link_iops = {
+ .readlink = generic_readlink,
+ .follow_link = hostfs_follow_link,
+ .put_link = hostfs_put_link,
};
static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent)