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 04/12] ima: Free the entire rule if it fails to parse
Date: Mon, 22 Jun 2020 19:32:28 -0500 [thread overview]
Message-ID: <20200623003236.830149-5-tyhicks@linux.microsoft.com> (raw)
In-Reply-To: <20200623003236.830149-1-tyhicks@linux.microsoft.com>
Use ima_free_rule() to fix memory leaks of allocated ima_rule_entry
members, such as .fsname and .keyrings, when an error is encountered
during rule parsing.
Set the args_p pointer to NULL after freeing it in the error path of
ima_lsm_rule_init() so that it isn't freed twice.
This fixes a memory leak seen when loading an rule that contains an
additional piece of allocated memory, such as an fsname, followed by an
invalid conditional:
# echo "measure fsname=tmpfs bad=cond" > /sys/kernel/security/ima/policy
-bash: echo: write error: Invalid argument
# echo scan > /sys/kernel/debug/kmemleak
# cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff98e7e4ece6c0 (size 8):
comm "bash", pid 672, jiffies 4294791843 (age 21.855s)
hex dump (first 8 bytes):
74 6d 70 66 73 00 6b a5 tmpfs.k.
backtrace:
[<00000000abab7413>] kstrdup+0x2e/0x60
[<00000000f11ede32>] ima_parse_add_rule+0x7d4/0x1020
[<00000000f883dd7a>] ima_write_policy+0xab/0x1d0
[<00000000b17cf753>] vfs_write+0xde/0x1d0
[<00000000b8ddfdea>] ksys_write+0x68/0xe0
[<00000000b8e21e87>] do_syscall_64+0x56/0xa0
[<0000000089ea7b98>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes: f1b08bbcbdaf ("ima: define a new policy condition based on the filesystem name")
Fixes: 2b60c0ecedf8 ("IMA: Read keyrings= option from the IMA policy")
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
---
security/integrity/ima/ima_policy.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 94ca3b8abb69..ee5152ecd3d9 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -919,6 +919,7 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry,
if (ima_rules == &ima_default_rules) {
kfree(entry->lsm[lsm_rule].args_p);
+ entry->lsm[lsm_rule].args_p = NULL;
result = -EINVAL;
} else
result = 0;
@@ -1410,7 +1411,7 @@ ssize_t ima_parse_add_rule(char *rule)
result = ima_parse_rule(p, entry);
if (result) {
- kfree(entry);
+ ima_free_rule(entry);
integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
NULL, op, "invalid-policy", result,
audit_info);
--
2.25.1
next prev parent reply other threads:[~2020-06-23 0:35 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 ` [PATCH 02/12] ima: Create a function to free a rule entry Tyler Hicks
2020-06-25 19:33 ` 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 ` Tyler Hicks [this message]
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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