From: Tyler Hicks <tyhicks@linux.microsoft.com>
To: Mimi Zohar <zohar@linux.ibm.com>,
Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: James Morris <jmorris@namei.org>,
"Serge E . Hallyn" <serge@hallyn.com>,
Lakshmi Ramasubramanian <nramas@linux.microsoft.com>,
Prakhar Srivastava <prsriva02@gmail.com>,
linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org,
linux-security-module@vger.kernel.org
Subject: [PATCH 02/12] ima: Create a function to free a rule entry
Date: Mon, 22 Jun 2020 19:32:26 -0500 [thread overview]
Message-ID: <20200623003236.830149-3-tyhicks@linux.microsoft.com> (raw)
In-Reply-To: <20200623003236.830149-1-tyhicks@linux.microsoft.com>
There are several possible pieces of allocated memory in a rule entry.
Create a function that can free all allocated memory for a given rule
entry.
This patch introduces no functional changes but sets the groundwork for
some memory leak fixes.
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
---
security/integrity/ima/ima_policy.c | 33 +++++++++++++++++++++++++++--
1 file changed, 31 insertions(+), 2 deletions(-)
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 236a731492d1..1320333201c6 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -261,6 +261,27 @@ static void ima_lsm_free_rule(struct ima_rule_entry *entry)
security_filter_rule_free(entry->lsm[i].rule);
kfree(entry->lsm[i].args_p);
}
+}
+
+static void ima_free_rule(struct ima_rule_entry *entry)
+{
+ if (!entry)
+ return;
+
+ /*
+ * entry->template->fields may be allocated in ima_parse_rule() but that
+ * reference is owned by the corresponding ima_template_desc element in
+ * the defined_templates list and cannot be freed here
+ */
+
+ /*
+ * When freeing newly added ima_rule_entry members, consider if you
+ * need to disown any references after the shallow copy in
+ * ima_lsm_copy_rule()
+ */
+ kfree(entry->fsname);
+ kfree(entry->keyrings);
+ ima_lsm_free_rule(entry);
kfree(entry);
}
@@ -298,10 +319,18 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry)
pr_warn("rule for LSM \'%s\' is undefined\n",
(char *)entry->lsm[i].args_p);
}
+
+ /* Disown all references that were shallow copied */
+ entry->fsname = NULL;
+ entry->keyrings = NULL;
+ entry->template = NULL;
return nentry;
out_err:
- ima_lsm_free_rule(nentry);
+ nentry->fsname = NULL;
+ nentry->keyrings = NULL;
+ nentry->template = NULL;
+ ima_free_rule(nentry);
return NULL;
}
@@ -315,7 +344,7 @@ static int ima_lsm_update_rule(struct ima_rule_entry *entry)
list_replace_rcu(&entry->list, &nentry->list);
synchronize_rcu();
- ima_lsm_free_rule(entry);
+ ima_free_rule(entry);
return 0;
}
--
2.25.1
next prev parent reply other threads:[~2020-06-23 0:34 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-23 0:32 [PATCH 00/12] ima: Fix rule parsing bugs and extend KEXEC_CMDLINE rule support Tyler Hicks
2020-06-23 0:32 ` [PATCH 01/12] ima: Have the LSM free its audit rule Tyler Hicks
2020-06-23 0:55 ` Casey Schaufler
2020-06-23 3:04 ` Tyler Hicks
2020-06-23 23:04 ` Tyler Hicks
2020-06-25 19:41 ` Mimi Zohar
2020-06-23 0:32 ` Tyler Hicks [this message]
2020-06-25 19:33 ` [PATCH 02/12] ima: Create a function to free a rule entry Mimi Zohar
2020-06-25 19:56 ` Tyler Hicks
2020-06-25 20:32 ` Mimi Zohar
2020-06-23 0:32 ` [PATCH 03/12] ima: Free the entire rule when deleting a list of rules Tyler Hicks
2020-06-25 21:05 ` Mimi Zohar
2020-06-25 21:07 ` Mimi Zohar
2020-06-25 21:08 ` Mimi Zohar
2020-06-23 0:32 ` [PATCH 04/12] ima: Free the entire rule if it fails to parse Tyler Hicks
2020-06-23 0:32 ` [PATCH 05/12] ima: Fail rule parsing when buffer hook functions have an invalid action Tyler Hicks
2020-06-25 21:51 ` Mimi Zohar
2020-06-23 0:32 ` [PATCH 06/12] ima: Fail rule parsing when the KEXEC_CMDLINE hook is combined with an invalid cond Tyler Hicks
2020-06-25 21:53 ` Mimi Zohar
2020-06-23 0:32 ` [PATCH 07/12] ima: Fail rule parsing when the KEY_CHECK " Tyler Hicks
2020-06-23 0:32 ` [PATCH 08/12] ima: Shallow copy the args_p member of ima_rule_entry.lsm elements Tyler Hicks
2020-06-25 21:18 ` Mimi Zohar
2020-06-23 0:32 ` [PATCH 09/12] ima: Use correct type for " Tyler Hicks
2020-06-25 21:20 ` Mimi Zohar
2020-06-23 0:32 ` [PATCH 10/12] ima: Move validation of the keyrings conditional into ima_validate_rule() Tyler Hicks
2020-06-25 19:50 ` Tyler Hicks
2020-06-25 20:46 ` Mimi Zohar
2020-06-23 0:32 ` [PATCH 11/12] ima: Use the common function to detect LSM conditionals in a rule Tyler Hicks
2020-06-25 22:45 ` Mimi Zohar
2020-06-23 0:32 ` [PATCH 12/12] ima: Support additional conditionals in the KEXEC_CMDLINE hook function Tyler Hicks
2020-06-25 22:56 ` Mimi Zohar
2020-06-25 22:59 ` Tyler Hicks
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