sysctl: Add ctl_table chains into cstring paths

For any component of table passed to __register_sysctl_paths
that actually serves as a path, add that to the cstring path
that is passed to __register_sysctl_table.

The result is that for most calls to __register_sysctl_paths
we only pass a table to __register_sysctl_table that contains
no child directories.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 5704ff0e889f..9b91deeeb56c 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -1076,6 +1076,7 @@ struct ctl_table_header *__register_sysctl_paths(
         struct nsproxy *namespaces,
         const struct ctl_path *path, struct ctl_table *table)
 {
+        struct ctl_table *ctl_table_arg = table;
         struct ctl_table_header *header = NULL;
         const struct ctl_path *component;
         char *new_path, *pos;
@@ -1090,7 +1091,15 @@ struct ctl_table_header *__register_sysctl_paths(
                 if (!pos)
                         goto out;
         }
+        while (table->procname && table->child && !table[1].procname) {
+                pos = append_path(new_path, pos, table->procname);
+                if (!pos)
+                        goto out;
+                table = table->child;
+        }
         header = __register_sysctl_table(root, namespaces, new_path, table);
+        if (header)
+                header->ctl_table_arg = ctl_table_arg;
 out:
         kfree(new_path);
         return header;