From d9d9ec6e2c45b22282cd36cf92fcb23d504350a8 Mon Sep 17 00:00:00 2001 From: Dustin Kirkland Date: Thu, 16 Feb 2006 13:40:01 -0600 Subject: [PATCH] [PATCH] Fix audit operators Darrel Goeddel initiated a discussion on IRC regarding the possibility of audit_comparator() returning -EINVAL signaling an invalid operator. It is possible when creating the rule to assure that the operator is one of the 6 sane values. Here's a snip from include/linux/audit.h Note that 0 (nonsense) and 7 (all operators) are not valid values for an operator. ... /* 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 */ ... Furthermore, prior to adding these extended operators, flagging the AUDIT_NEGATE bit implied !=, and otherwise == was assumed. The following code forces the operator to be != if the AUDIT_NEGATE bit was flipped on. And if no operator was specified, == is assumed. The only invalid condition is if the AUDIT_NEGATE bit is off and all of the AUDIT_EQUAL, AUDIT_LESS_THAN, and AUDIT_GREATER_THAN bits are on--clearly a nonsensical operator. Now that this is handled at rule insertion time, the default -EINVAL return of audit_comparator() is eliminated such that the function can only return 1 or 0. If this is acceptable, let's get this applied to the current tree. :-Dustin -- Signed-off-by: Al Viro (cherry picked from 9bf0a8e137040f87d1b563336d4194e38fb2ba1a commit) --- kernel/auditfilter.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index 35f8fa82bb8..b85fd8cce11 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -160,11 +160,17 @@ static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule) f->val = rule->values[i]; entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1; + + /* Support for legacy operators where + * AUDIT_NEGATE bit signifies != and otherwise assumes == */ if (f->op & AUDIT_NEGATE) - f->op |= AUDIT_NOT_EQUAL; - else if (!(f->op & AUDIT_OPERATORS)) - f->op |= AUDIT_EQUAL; - f->op &= ~AUDIT_NEGATE; + f->op = AUDIT_NOT_EQUAL; + else if (!f->op) + f->op = AUDIT_EQUAL; + else if (f->op == AUDIT_OPERATORS) { + err = -EINVAL; + goto exit_free; + } } exit_nofree: @@ -533,9 +539,9 @@ int audit_comparator(const u32 left, const u32 op, const u32 right) return (left > right); case AUDIT_GREATER_THAN_OR_EQUAL: return (left >= right); - default: - return -EINVAL; } + BUG(); + return 0; }