proc: add and remove /proc entry create checks

[karo-tx-linux.git] / fs / proc / generic.c

diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index b7f268eb5f45251ae1977c643540e081c6612546..190862e8988059bc53c4fce415dd3b113703c623 100644 (file)
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -330,28 +330,28 @@ static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
                                          nlink_t nlink)
 {
        struct proc_dir_entry *ent = NULL;
-       const char *fn = name;
-       unsigned int len;
-
-       /* make sure name is valid */
-       if (!name || !strlen(name))
-               goto out;
+       const char *fn;
+       struct qstr qstr;
 
        if (xlate_proc_name(name, parent, &fn) != 0)
                goto out;
+       qstr.name = fn;
+       qstr.len = strlen(fn);
+       if (qstr.len == 0 || qstr.len >= 256) {
+               WARN(1, "name len %u\n", qstr.len);
+               return NULL;
+       }
+       if (*parent == &proc_root && name_to_int(&qstr) != ~0U) {
+               WARN(1, "create '/proc/%s' by hand\n", qstr.name);
+               return NULL;
+       }
 
-       /* At this point there must not be any '/' characters beyond *fn */
-       if (strchr(fn, '/'))
-               goto out;
-
-       len = strlen(fn);
-
-       ent = kzalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL);
+       ent = kzalloc(sizeof(struct proc_dir_entry) + qstr.len + 1, GFP_KERNEL);
        if (!ent)
                goto out;
 
-       memcpy(ent->name, fn, len + 1);
-       ent->namelen = len;
+       memcpy(ent->name, fn, qstr.len + 1);
+       ent->namelen = qstr.len;
        ent->mode = mode;
        ent->nlink = nlink;
        atomic_set(&ent->count, 1);