| From 073770739df181d69e71fc1db4cd466c35b1c732 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Thu, 9 Jul 2020 01:19:02 -0500 |
| Subject: ima: Free the entire rule if it fails to parse |
| |
| From: Tyler Hicks <tyhicks@linux.microsoft.com> |
| |
| [ Upstream commit 2bdd737c5687d6dec30e205953146ede8a87dbdd ] |
| |
| 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> |
| Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| 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 641582230861c..18271920d315d 100644 |
| --- a/security/integrity/ima/ima_policy.c |
| +++ b/security/integrity/ima/ima_policy.c |
| @@ -913,6 +913,7 @@ 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; |
| @@ -1404,7 +1405,7 @@ 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 |
| |