From: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.
===============
commit 4351c294b8c1028077280f761e158d167b592974 upstream.
The current "mask" policy option matches files opened as MAY_READ,
MAY_WRITE, MAY_APPEND or MAY_EXEC. This patch extends the "mask"
option to match files opened containing one of these modes. For
example, "mask=^MAY_READ" would match files opened read-write.
Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Dr. Greg Wettstein <gw@xxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
Documentation/ABI/testing/ima_policy | 3 ++-
security/integrity/ima/ima_policy.c | 20 +++++++++++++++-----
2 files changed, 17 insertions(+), 6 deletions(-)
diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
index 84c6a9c1c531..750ab970fa95 100644
--- a/Documentation/ABI/testing/ima_policy
+++ b/Documentation/ABI/testing/ima_policy
@@ -26,7 +26,8 @@ Description:
option: [[appraise_type=]] [permit_directio]
base: func:= [BPRM_CHECK][MMAP_CHECK][FILE_CHECK][MODULE_CHECK]
- mask:= [MAY_READ] [MAY_WRITE] [MAY_APPEND] [MAY_EXEC]
+ mask:= [[^]MAY_READ] [[^]MAY_WRITE] [[^]MAY_APPEND]
+ [[^]MAY_EXEC]
fsmagic:= hex value
fsuuid:= file system UUID (e.g 8bcbe394-4f13-4144-be8e-5aa9ea2ce2f6)
uid:= decimal value
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index bab08da010ee..9d8e420a80d9 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -27,6 +27,7 @@
#define IMA_UID 0x0008
#define IMA_FOWNER 0x0010
#define IMA_FSUUID 0x0020
+#define IMA_INMASK 0x0040
#define IMA_EUID 0x0080
#define UNKNOWN 0
@@ -172,6 +173,9 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
return false;
if ((rule->flags & IMA_MASK) && rule->mask != mask)
return false;
+ if ((rule->flags & IMA_INMASK) &&
+ (!(rule->mask & mask) && func != POST_SETATTR))
+ return false;
if ((rule->flags & IMA_FSMAGIC)
&& rule->fsmagic != inode->i_sb->s_magic)
return false;
@@ -425,6 +429,7 @@ static void ima_log_string(struct audit_buffer *ab, char *key, char *value)
static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
{
struct audit_buffer *ab;
+ char *from;
char *p;
int result = 0;
@@ -513,18 +518,23 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
if (entry->mask)
result = -EINVAL;
- if ((strcmp(args[0].from, "MAY_EXEC")) == 0)
+ from = args[0].from;
+ if (*from == '^')
+ from++;
+
+ if ((strcmp(from, "MAY_EXEC")) == 0)
entry->mask = MAY_EXEC;
- else if (strcmp(args[0].from, "MAY_WRITE") == 0)
+ else if (strcmp(from, "MAY_WRITE") == 0)
entry->mask = MAY_WRITE;
- else if (strcmp(args[0].from, "MAY_READ") == 0)
+ else if (strcmp(from, "MAY_READ") == 0)
entry->mask = MAY_READ;
- else if (strcmp(args[0].from, "MAY_APPEND") == 0)
+ else if (strcmp(from, "MAY_APPEND") == 0)
entry->mask = MAY_APPEND;
else
result = -EINVAL;
if (!result)
- entry->flags |= IMA_MASK;
+ entry->flags |= (*args[0].from == '^')
+ ? IMA_INMASK : IMA_MASK;
break;
case Opt_fsmagic:
ima_log_string(ab, "fsmagic", args[0].from);
--
2.5.0
--
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