[PATCH] allow audit filtering on bit & operations

Right now the audit filter can match on = != > < >= blah blah blah.
This allow the filter to also look at bitwise AND operations, &

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Eric Paris 2007-06-04 17:00:14 -04:00 committed by Al Viro
parent c926e4f432
commit 74f2345b6b
2 changed files with 28 additions and 13 deletions

View file

@ -161,7 +161,7 @@
* are currently used in an audit field constant understood by the kernel.
* If you are adding a new #define AUDIT_<whatever>, please ensure that
* AUDIT_UNUSED_BITS is updated if need be. */
#define AUDIT_UNUSED_BITS 0x0FFFFC00
#define AUDIT_UNUSED_BITS 0x07FFFC00
/* Rule fields */
@ -213,25 +213,29 @@
#define AUDIT_NEGATE 0x80000000
/* These are the supported operators.
* 4 2 1
* = > <
* -------
* 0 0 0 0 nonsense
* 0 0 1 1 <
* 0 1 0 2 >
* 0 1 1 3 !=
* 1 0 0 4 =
* 1 0 1 5 <=
* 1 1 0 6 >=
* 1 1 1 7 all operators
* 4 2 1 8
* = > < ?
* ----------
* 0 0 0 0 00 nonsense
* 0 0 0 1 08 & bit mask
* 0 0 1 0 10 <
* 0 1 0 0 20 >
* 0 1 1 0 30 !=
* 1 0 0 0 40 =
* 1 0 0 1 48 &= bit test
* 1 0 1 0 50 <=
* 1 1 0 0 60 >=
* 1 1 1 1 78 all operators
*/
#define AUDIT_BIT_MASK 0x08000000
#define AUDIT_LESS_THAN 0x10000000
#define AUDIT_GREATER_THAN 0x20000000
#define AUDIT_NOT_EQUAL 0x30000000
#define AUDIT_EQUAL 0x40000000
#define AUDIT_BIT_TEST (AUDIT_BIT_MASK|AUDIT_EQUAL)
#define AUDIT_LESS_THAN_OR_EQUAL (AUDIT_LESS_THAN|AUDIT_EQUAL)
#define AUDIT_GREATER_THAN_OR_EQUAL (AUDIT_GREATER_THAN|AUDIT_EQUAL)
#define AUDIT_OPERATORS (AUDIT_EQUAL|AUDIT_NOT_EQUAL)
#define AUDIT_OPERATORS (AUDIT_EQUAL|AUDIT_NOT_EQUAL|AUDIT_BIT_MASK)
/* Status symbols */
/* Mask values */

View file

@ -456,6 +456,13 @@ static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
case AUDIT_DEVMINOR:
case AUDIT_EXIT:
case AUDIT_SUCCESS:
/* bit ops are only useful on syscall args */
if (f->op == AUDIT_BIT_MASK ||
f->op == AUDIT_BIT_TEST) {
err = -EINVAL;
goto exit_free;
}
break;
case AUDIT_ARG0:
case AUDIT_ARG1:
case AUDIT_ARG2:
@ -1566,6 +1573,10 @@ int audit_comparator(const u32 left, const u32 op, const u32 right)
return (left > right);
case AUDIT_GREATER_THAN_OR_EQUAL:
return (left >= right);
case AUDIT_BIT_MASK:
return (left & right);
case AUDIT_BIT_TEST:
return ((left & right) == right);
}
BUG();
return 0;