queue-4.4/audit-fix-a-memory-leak-bug.patch

   1 From 9ef43ada1a0f14c29b9940e3407bf53aae420394 Mon Sep 17 00:00:00 2001
   2 From: Wenwen Wang <wang6495@umn.edu>
   3 Date: Fri, 19 Apr 2019 20:49:29 -0500
   4 Subject: audit: fix a memory leak bug
   5
   6 [ Upstream commit 70c4cf17e445264453bc5323db3e50aa0ac9e81f ]
   7
   8 In audit_rule_change(), audit_data_to_entry() is firstly invoked to
   9 translate the payload data to the kernel's rule representation. In
  10 audit_data_to_entry(), depending on the audit field type, an audit tree may
  11 be created in audit_make_tree(), which eventually invokes kmalloc() to
  12 allocate the tree.  Since this tree is a temporary tree, it will be then
  13 freed in the following execution, e.g., audit_add_rule() if the message
  14 type is AUDIT_ADD_RULE or audit_del_rule() if the message type is
  15 AUDIT_DEL_RULE. However, if the message type is neither AUDIT_ADD_RULE nor
  16 AUDIT_DEL_RULE, i.e., the default case of the switch statement, this
  17 temporary tree is not freed.
  18
  19 To fix this issue, only allocate the tree when the type is AUDIT_ADD_RULE
  20 or AUDIT_DEL_RULE.
  21
  22 Signed-off-by: Wenwen Wang <wang6495@umn.edu>
  23 Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
  24 Signed-off-by: Paul Moore <paul@paul-moore.com>
  25 Signed-off-by: Sasha Levin <sashal@kernel.org>
  26 ---
  27  kernel/auditfilter.c | 12 +++++++-----
  28  1 file changed, 7 insertions(+), 5 deletions(-)
  29
  30 diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
  31 index b57f929f1b468..cf7aa656b308b 100644
  32 --- a/kernel/auditfilter.c
  33 +++ b/kernel/auditfilter.c
  34 @@ -1095,22 +1095,24 @@ int audit_rule_change(int type, __u32 portid, int seq, void *data,
  35         int err = 0;
  36         struct audit_entry *entry;
  37
  38 -       entry = audit_data_to_entry(data, datasz);
  39 -       if (IS_ERR(entry))
  40 -               return PTR_ERR(entry);
  41 -
  42         switch (type) {
  43         case AUDIT_ADD_RULE:
  44 +               entry = audit_data_to_entry(data, datasz);
  45 +               if (IS_ERR(entry))
  46 +                       return PTR_ERR(entry);
  47                 err = audit_add_rule(entry);
  48                 audit_log_rule_change("add_rule", &entry->rule, !err);
  49                 break;
  50         case AUDIT_DEL_RULE:
  51 +               entry = audit_data_to_entry(data, datasz);
  52 +               if (IS_ERR(entry))
  53 +                       return PTR_ERR(entry);
  54                 err = audit_del_rule(entry);
  55                 audit_log_rule_change("remove_rule", &entry->rule, !err);
  56                 break;
  57         default:
  58 -               err = -EINVAL;
  59                 WARN_ON(1);
  60 +               return -EINVAL;
  61         }
  62
  63         if (err || type == AUDIT_DEL_RULE) {
  64 --
  65 2.20.1
  66