Use access mode instead of open flags to determine needed permissions (CVE-2008-0001)

[karo-tx-linux.git] / fs / namei.c

diff --git a/fs/namei.c b/fs/namei.c
index 3bdb29615a9d7e2655601c7151b4496c80b1a74b..314afe60889191b17bdefd8c5ac25cbee7345f0a 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -107,6 +107,8 @@
  * any extra contention...
  */
 
+static int fastcall link_path_walk(const char *name, struct nameidata *nd);
+
 /* In order to reduce some races, while at the same time doing additional
  * checking and hopefully speeding things up, we copy filenames to the
  * kernel data space before using them..
@@ -998,7 +1000,7 @@ return_err:
  * Retry the whole path once, forcing real lookup requests
  * instead of relying on the dcache.
  */
-int fastcall link_path_walk(const char *name, struct nameidata *nd)
+static int fastcall link_path_walk(const char *name, struct nameidata *nd)
 {
        struct nameidata save = *nd;
        int result;
@@ -1022,7 +1024,7 @@ int fastcall link_path_walk(const char *name, struct nameidata *nd)
        return result;
 }
 
-int fastcall path_walk(const char * name, struct nameidata *nd)
+static int fastcall path_walk(const char * name, struct nameidata *nd)
 {
        current->total_link_count = 0;
        return link_path_walk(name, nd);
@@ -1574,7 +1576,7 @@ int may_open(struct nameidata *nd, int acc_mode, int flag)
        if (S_ISLNK(inode->i_mode))
                return -ELOOP;
        
-       if (S_ISDIR(inode->i_mode) && (flag & FMODE_WRITE))
+       if (S_ISDIR(inode->i_mode) && (acc_mode & MAY_WRITE))
                return -EISDIR;
 
        error = vfs_permission(nd, acc_mode);
@@ -1593,7 +1595,7 @@ int may_open(struct nameidata *nd, int acc_mode, int flag)
                        return -EACCES;
 
                flag &= ~O_TRUNC;
-       } else if (IS_RDONLY(inode) && (flag & FMODE_WRITE))
+       } else if (IS_RDONLY(inode) && (acc_mode & MAY_WRITE))
                return -EROFS;
        /*
         * An append-only file must be opened in append mode for writing.
@@ -2807,7 +2809,6 @@ EXPORT_SYMBOL(page_symlink_inode_operations);
 EXPORT_SYMBOL(path_lookup);
 EXPORT_SYMBOL(vfs_path_lookup);
 EXPORT_SYMBOL(path_release);
-EXPORT_SYMBOL(path_walk);
 EXPORT_SYMBOL(permission);
 EXPORT_SYMBOL(vfs_permission);
 EXPORT_SYMBOL(file_permission);