[RFC,ghak90,(was,ghak32),V3,06/10] audit: add containerid filtering

Submitted by Richard Guy Briggs on June 6, 2018, 4:58 p.m.

Details

Message ID cc924bc23937ea3d65b4b2b625796ee61a5fb4da.1528304204.git.rgb@redhat.com
State New
Series "audit: implement container identifier"
Headers show

Commit Message

Richard Guy Briggs June 6, 2018, 4:58 p.m.
Implement audit container identifier filtering using the AUDIT_CONTID
field name to send an 8-character string representing a u64 since the
value field is only u32.

Sending it as two u32 was considered, but gathering and comparing two
fields was more complex.

The feature indicator is AUDIT_FEATURE_BITMAP_CONTAINERID_FILTER.

See: https://github.com/linux-audit/audit-kernel/issues/91
See: https://github.com/linux-audit/audit-userspace/issues/40
See: https://github.com/linux-audit/audit-testsuite/issues/64
See: https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Container-ID
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
---
 include/linux/audit.h      |  1 +
 include/uapi/linux/audit.h |  5 ++++-
 kernel/audit.h             |  1 +
 kernel/auditfilter.c       | 47 ++++++++++++++++++++++++++++++++++++++++++++++
 kernel/auditsc.c           |  3 +++
 5 files changed, 56 insertions(+), 1 deletion(-)

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diff --git a/include/linux/audit.h b/include/linux/audit.h
index f549121..1e37abf 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -76,6 +76,7 @@  struct audit_field {
 	u32				type;
 	union {
 		u32			val;
+		u64			val64;
 		kuid_t			uid;
 		kgid_t			gid;
 		struct {
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index 469ab25..b440558 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -262,6 +262,7 @@ 
 #define AUDIT_LOGINUID_SET	24
 #define AUDIT_SESSIONID	25	/* Session ID */
 #define AUDIT_FSTYPE	26	/* FileSystem Type */
+#define AUDIT_CONTID	27	/* Container ID */
 
 				/* These are ONLY useful when checking
 				 * at syscall exit time (AUDIT_AT_EXIT). */
@@ -342,6 +343,7 @@  enum {
 #define AUDIT_FEATURE_BITMAP_SESSIONID_FILTER	0x00000010
 #define AUDIT_FEATURE_BITMAP_LOST_RESET		0x00000020
 #define AUDIT_FEATURE_BITMAP_FILTER_FS		0x00000040
+#define AUDIT_FEATURE_BITMAP_CONTAINERID_FILTER	0x00000080
 
 #define AUDIT_FEATURE_BITMAP_ALL (AUDIT_FEATURE_BITMAP_BACKLOG_LIMIT | \
 				  AUDIT_FEATURE_BITMAP_BACKLOG_WAIT_TIME | \
@@ -349,7 +351,8 @@  enum {
 				  AUDIT_FEATURE_BITMAP_EXCLUDE_EXTEND | \
 				  AUDIT_FEATURE_BITMAP_SESSIONID_FILTER | \
 				  AUDIT_FEATURE_BITMAP_LOST_RESET | \
-				  AUDIT_FEATURE_BITMAP_FILTER_FS)
+				  AUDIT_FEATURE_BITMAP_FILTER_FS | \
+				  AUDIT_FEATURE_BITMAP_CONTAINERID_FILTER)
 
 /* deprecated: AUDIT_VERSION_* */
 #define AUDIT_VERSION_LATEST 		AUDIT_FEATURE_BITMAP_ALL
diff --git a/kernel/audit.h b/kernel/audit.h
index 1cf1c35..743d445 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -235,6 +235,7 @@  static inline int audit_hash_ino(u32 ino)
 
 extern int audit_match_class(int class, unsigned syscall);
 extern int audit_comparator(const u32 left, const u32 op, const u32 right);
+extern int audit_comparator64(const u64 left, const u32 op, const u64 right);
 extern int audit_uid_comparator(kuid_t left, u32 op, kuid_t right);
 extern int audit_gid_comparator(kgid_t left, u32 op, kgid_t right);
 extern int parent_len(const char *path);
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index eaa3201..a5f60ce 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -410,6 +410,7 @@  static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
 	/* FALL THROUGH */
 	case AUDIT_ARCH:
 	case AUDIT_FSTYPE:
+	case AUDIT_CONTID:
 		if (f->op != Audit_not_equal && f->op != Audit_equal)
 			return -EINVAL;
 		break;
@@ -584,6 +585,14 @@  static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
 			}
 			entry->rule.exe = audit_mark;
 			break;
+		case AUDIT_CONTID:
+			if (f->val != sizeof(u64))
+				goto exit_free;
+			str = audit_unpack_string(&bufp, &remain, f->val);
+			if (IS_ERR(str))
+				goto exit_free;
+			f->val64 = ((u64 *)str)[0];
+			break;
 		}
 	}
 
@@ -666,6 +675,11 @@  static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
 			data->buflen += data->values[i] =
 				audit_pack_string(&bufp, audit_mark_path(krule->exe));
 			break;
+		case AUDIT_CONTID:
+			data->buflen += data->values[i] = sizeof(u64);
+			for (i = 0; i < sizeof(u64); i++)
+				((char *)bufp)[i] = ((char *)&f->val64)[i];
+			break;
 		case AUDIT_LOGINUID_SET:
 			if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
 				data->fields[i] = AUDIT_LOGINUID;
@@ -752,6 +766,10 @@  static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
 			if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
 				return 1;
 			break;
+		case AUDIT_CONTID:
+			if (a->fields[i].val64 != b->fields[i].val64)
+				return 1;
+			break;
 		default:
 			if (a->fields[i].val != b->fields[i].val)
 				return 1;
@@ -1208,6 +1226,31 @@  int audit_comparator(u32 left, u32 op, u32 right)
 	}
 }
 
+int audit_comparator64(u64 left, u32 op, u64 right)
+{
+	switch (op) {
+	case Audit_equal:
+		return (left == right);
+	case Audit_not_equal:
+		return (left != right);
+	case Audit_lt:
+		return (left < right);
+	case Audit_le:
+		return (left <= right);
+	case Audit_gt:
+		return (left > right);
+	case Audit_ge:
+		return (left >= right);
+	case Audit_bitmask:
+		return (left & right);
+	case Audit_bittest:
+		return ((left & right) == right);
+	default:
+		BUG();
+		return 0;
+	}
+}
+
 int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
 {
 	switch (op) {
@@ -1346,6 +1389,10 @@  int audit_filter(int msgtype, unsigned int listtype)
 				result = audit_comparator(audit_loginuid_set(current),
 							  f->op, f->val);
 				break;
+			case AUDIT_CONTID:
+				result = audit_comparator64(audit_get_contid(current),
+							      f->op, f->val64);
+				break;
 			case AUDIT_MSGTYPE:
 				result = audit_comparator(msgtype, f->op, f->val);
 				break;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 81c9765..ea1ee35 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -622,6 +622,9 @@  static int audit_filter_rules(struct task_struct *tsk,
 		case AUDIT_LOGINUID_SET:
 			result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val);
 			break;
+		case AUDIT_CONTID:
+			result = audit_comparator64(audit_get_contid(tsk), f->op, f->val64);
+			break;
 		case AUDIT_SUBJ_USER:
 		case AUDIT_SUBJ_ROLE:
 		case AUDIT_SUBJ_TYPE:

Comments

Paul Moore July 20, 2018, 10:14 p.m.
On Wed, Jun 6, 2018 at 1:03 PM Richard Guy Briggs <rgb@redhat.com> wrote:
> Implement audit container identifier filtering using the AUDIT_CONTID
> field name to send an 8-character string representing a u64 since the
> value field is only u32.
>
> Sending it as two u32 was considered, but gathering and comparing two
> fields was more complex.
>
> The feature indicator is AUDIT_FEATURE_BITMAP_CONTAINERID_FILTER.

We've had some discussions about starting to be a bit more "stingy"
with our feature bitmap fields, and normally I'm not sure I would want
to burn one on a new filter (we should be able to fail safely here),
but considering the significance of the audit container ID work I
think it might be okay to burn a bit :)

How about renaming this to just AUDIT_FEATURE_BITMAP_CONTAINERID?

> See: https://github.com/linux-audit/audit-kernel/issues/91
> See: https://github.com/linux-audit/audit-userspace/issues/40
> See: https://github.com/linux-audit/audit-testsuite/issues/64
> See: https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Container-ID
> Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
> ---
>  include/linux/audit.h      |  1 +
>  include/uapi/linux/audit.h |  5 ++++-
>  kernel/audit.h             |  1 +
>  kernel/auditfilter.c       | 47 ++++++++++++++++++++++++++++++++++++++++++++++
>  kernel/auditsc.c           |  3 +++
>  5 files changed, 56 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/audit.h b/include/linux/audit.h
> index f549121..1e37abf 100644
> --- a/include/linux/audit.h
> +++ b/include/linux/audit.h
> @@ -76,6 +76,7 @@ struct audit_field {
>         u32                             type;
>         union {
>                 u32                     val;
> +               u64                     val64;
>                 kuid_t                  uid;
>                 kgid_t                  gid;
>                 struct {
> diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
> index 469ab25..b440558 100644
> --- a/include/uapi/linux/audit.h
> +++ b/include/uapi/linux/audit.h
> @@ -262,6 +262,7 @@
>  #define AUDIT_LOGINUID_SET     24
>  #define AUDIT_SESSIONID        25      /* Session ID */
>  #define AUDIT_FSTYPE   26      /* FileSystem Type */
> +#define AUDIT_CONTID   27      /* Container ID */
>
>                                 /* These are ONLY useful when checking
>                                  * at syscall exit time (AUDIT_AT_EXIT). */
> @@ -342,6 +343,7 @@ enum {
>  #define AUDIT_FEATURE_BITMAP_SESSIONID_FILTER  0x00000010
>  #define AUDIT_FEATURE_BITMAP_LOST_RESET                0x00000020
>  #define AUDIT_FEATURE_BITMAP_FILTER_FS         0x00000040
> +#define AUDIT_FEATURE_BITMAP_CONTAINERID_FILTER        0x00000080
>
>  #define AUDIT_FEATURE_BITMAP_ALL (AUDIT_FEATURE_BITMAP_BACKLOG_LIMIT | \
>                                   AUDIT_FEATURE_BITMAP_BACKLOG_WAIT_TIME | \
> @@ -349,7 +351,8 @@ enum {
>                                   AUDIT_FEATURE_BITMAP_EXCLUDE_EXTEND | \
>                                   AUDIT_FEATURE_BITMAP_SESSIONID_FILTER | \
>                                   AUDIT_FEATURE_BITMAP_LOST_RESET | \
> -                                 AUDIT_FEATURE_BITMAP_FILTER_FS)
> +                                 AUDIT_FEATURE_BITMAP_FILTER_FS | \
> +                                 AUDIT_FEATURE_BITMAP_CONTAINERID_FILTER)
>
>  /* deprecated: AUDIT_VERSION_* */
>  #define AUDIT_VERSION_LATEST           AUDIT_FEATURE_BITMAP_ALL
> diff --git a/kernel/audit.h b/kernel/audit.h
> index 1cf1c35..743d445 100644
> --- a/kernel/audit.h
> +++ b/kernel/audit.h
> @@ -235,6 +235,7 @@ static inline int audit_hash_ino(u32 ino)
>
>  extern int audit_match_class(int class, unsigned syscall);
>  extern int audit_comparator(const u32 left, const u32 op, const u32 right);
> +extern int audit_comparator64(const u64 left, const u32 op, const u64 right);
>  extern int audit_uid_comparator(kuid_t left, u32 op, kuid_t right);
>  extern int audit_gid_comparator(kgid_t left, u32 op, kgid_t right);
>  extern int parent_len(const char *path);
> diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
> index eaa3201..a5f60ce 100644
> --- a/kernel/auditfilter.c
> +++ b/kernel/auditfilter.c
> @@ -410,6 +410,7 @@ static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
>         /* FALL THROUGH */
>         case AUDIT_ARCH:
>         case AUDIT_FSTYPE:
> +       case AUDIT_CONTID:
>                 if (f->op != Audit_not_equal && f->op != Audit_equal)
>                         return -EINVAL;
>                 break;
> @@ -584,6 +585,14 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
>                         }
>                         entry->rule.exe = audit_mark;
>                         break;
> +               case AUDIT_CONTID:
> +                       if (f->val != sizeof(u64))
> +                               goto exit_free;
> +                       str = audit_unpack_string(&bufp, &remain, f->val);
> +                       if (IS_ERR(str))
> +                               goto exit_free;
> +                       f->val64 = ((u64 *)str)[0];
> +                       break;
>                 }
>         }
>
> @@ -666,6 +675,11 @@ static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
>                         data->buflen += data->values[i] =
>                                 audit_pack_string(&bufp, audit_mark_path(krule->exe));
>                         break;
> +               case AUDIT_CONTID:
> +                       data->buflen += data->values[i] = sizeof(u64);
> +                       for (i = 0; i < sizeof(u64); i++)
> +                               ((char *)bufp)[i] = ((char *)&f->val64)[i];
> +                       break;
>                 case AUDIT_LOGINUID_SET:
>                         if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
>                                 data->fields[i] = AUDIT_LOGINUID;
> @@ -752,6 +766,10 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
>                         if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
>                                 return 1;
>                         break;
> +               case AUDIT_CONTID:
> +                       if (a->fields[i].val64 != b->fields[i].val64)
> +                               return 1;
> +                       break;
>                 default:
>                         if (a->fields[i].val != b->fields[i].val)
>                                 return 1;
> @@ -1208,6 +1226,31 @@ int audit_comparator(u32 left, u32 op, u32 right)
>         }
>  }
>
> +int audit_comparator64(u64 left, u32 op, u64 right)
> +{
> +       switch (op) {
> +       case Audit_equal:
> +               return (left == right);
> +       case Audit_not_equal:
> +               return (left != right);
> +       case Audit_lt:
> +               return (left < right);
> +       case Audit_le:
> +               return (left <= right);
> +       case Audit_gt:
> +               return (left > right);
> +       case Audit_ge:
> +               return (left >= right);
> +       case Audit_bitmask:
> +               return (left & right);
> +       case Audit_bittest:
> +               return ((left & right) == right);
> +       default:
> +               BUG();
> +               return 0;
> +       }
> +}
> +
>  int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
>  {
>         switch (op) {
> @@ -1346,6 +1389,10 @@ int audit_filter(int msgtype, unsigned int listtype)
>                                 result = audit_comparator(audit_loginuid_set(current),
>                                                           f->op, f->val);
>                                 break;
> +                       case AUDIT_CONTID:
> +                               result = audit_comparator64(audit_get_contid(current),
> +                                                             f->op, f->val64);
> +                               break;
>                         case AUDIT_MSGTYPE:
>                                 result = audit_comparator(msgtype, f->op, f->val);
>                                 break;
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 81c9765..ea1ee35 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -622,6 +622,9 @@ static int audit_filter_rules(struct task_struct *tsk,
>                 case AUDIT_LOGINUID_SET:
>                         result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val);
>                         break;
> +               case AUDIT_CONTID:
> +                       result = audit_comparator64(audit_get_contid(tsk), f->op, f->val64);
> +                       break;
>                 case AUDIT_SUBJ_USER:
>                 case AUDIT_SUBJ_ROLE:
>                 case AUDIT_SUBJ_TYPE:
> --
> 1.8.3.1
>
> --
> Linux-audit mailing list
> Linux-audit@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-audit



--
paul moore
www.paul-moore.com