This is a note to let you know that I've just added the patch titled
ima: fix add LSM rule bug
to the 2.6.36-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ima-fix-add-lsm-rule-bug.patch
and it can be found in the queue-2.6.36 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 867c20265459d30a01b021a9c1e81fb4c5832aa9 Mon Sep 17 00:00:00 2001
From: Mimi Zohar <[email protected]>
Date: Mon, 3 Jan 2011 14:59:10 -0800
Subject: ima: fix add LSM rule bug
From: Mimi Zohar <[email protected]>
commit 867c20265459d30a01b021a9c1e81fb4c5832aa9 upstream.
If security_filter_rule_init() doesn't return a rule, then not everything
is as fine as the return code implies.
This bug only occurs when the LSM (eg. SELinux) is disabled at runtime.
Adding an empty LSM rule causes ima_match_rules() to always succeed,
ignoring any remaining rules.
default IMA TCB policy:
# PROC_SUPER_MAGIC
dont_measure fsmagic=0x9fa0
# SYSFS_MAGIC
dont_measure fsmagic=0x62656572
# DEBUGFS_MAGIC
dont_measure fsmagic=0x64626720
# TMPFS_MAGIC
dont_measure fsmagic=0x01021994
# SECURITYFS_MAGIC
dont_measure fsmagic=0x73636673
< LSM specific rule >
dont_measure obj_type=var_log_t
measure func=BPRM_CHECK
measure func=FILE_MMAP mask=MAY_EXEC
measure func=FILE_CHECK mask=MAY_READ uid=0
Thus without the patch, with the boot parameters 'tcb selinux=0', adding
the above 'dont_measure obj_type=var_log_t' rule to the default IMA TCB
measurement policy, would result in nothing being measured. The patch
prevents the default TCB policy from being replaced.
Signed-off-by: Mimi Zohar <[email protected]>
Cc: James Morris <[email protected]>
Acked-by: Serge Hallyn <[email protected]>
Cc: David Safford <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
security/integrity/ima/ima_policy.c | 2 ++
1 file changed, 2 insertions(+)
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -253,6 +253,8 @@ static int ima_lsm_rule_init(struct ima_
result = security_filter_rule_init(entry->lsm[lsm_rule].type,
Audit_equal, args,
&entry->lsm[lsm_rule].rule);
+ if (!entry->lsm[lsm_rule].rule)
+ return -EINVAL;
return result;
}
Patches currently in stable-queue which might be from [email protected]
are
queue-2.6.36/ima-fix-add-lsm-rule-bug.patch
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