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| author | Mimi Zohar <zohar@linux.vnet.ibm.com> | 2014-11-05 07:53:55 -0500 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2015-08-19 08:36:50 +0200 |
| commit | a5423d5eede5d13f8102b3129f8cd7a0e717bd3e (patch) | |
| tree | 7dc2e08fcdf546bc9dda87a07e87eea131186601 | |
| parent | cee24cef75f5f5cbfce1160b9d8f7bd08466324f (diff) | |
| download | lwn-a5423d5eede5d13f8102b3129f8cd7a0e717bd3e.tar.gz lwn-a5423d5eede5d13f8102b3129f8cd7a0e717bd3e.zip | |
ima: extend "mask" policy matching support
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@linux.vnet.ibm.com>
Signed-off-by: Dr. Greg Wettstein <gw@idfusion.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| -rw-r--r-- | Documentation/ABI/testing/ima_policy | 3 | ||||
| -rw-r--r-- | 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); |