procfs: fix error handling of proc_register()

proc_register() error paths are leaking inodes and directory refcounts.

Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 1 deletions

diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 9f8fa1e5e8aa..be39c6feb3e5 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -369,14 +369,21 @@ static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp
                 dp->proc_iops = &proc_file_inode_operations;
         } else {
                 WARN_ON(1);
+                proc_free_inum(dp->low_ino);
                 return -EINVAL;
         }
 
         spin_lock(&proc_subdir_lock);
         dp->parent = dir;
-        if (pde_subdir_insert(dir, dp) == false)
+        if (pde_subdir_insert(dir, dp) == false) {
                 WARN(1, "proc_dir_entry '%s/%s' already registered\n",
                      dir->name, dp->name);
+                spin_unlock(&proc_subdir_lock);
+                if (S_ISDIR(dp->mode))
+                        dir->nlink--;
+                proc_free_inum(dp->low_ino);
+                return -EEXIST;
+        }
         spin_unlock(&proc_subdir_lock);
 
         return 0;