[PATCH] audit: restore AUDIT_LOGINUID unset ABI
A regression was caused by commit 780a7654cee8:
audit: Make testing for a valid loginuid explicit.
(which in turn attempted to fix a regression caused by e1760bd)
When audit_krule_to_data() fills in the rules to get a listing, there was a
missing clause to convert back from AUDIT_LOGINUID_SET to AUDIT_LOGINUID.
This broke userspace by not returning the same information that was sent and
expected.
The rule:
auditctl -a exit,never -F auid=-1
gives:
auditctl -l
LIST_RULES: exit,never f24=0 syscall=all
when it should give:
LIST_RULES: exit,never auid=-1 (0xffffffff) syscall=all
Tag it so that it is reported the same way it was set.
Note: move the field validation call ahead of the mutation code to have it work
on the original field set.
Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com>
---
include/uapi/linux/audit.h | 3 +++
kernel/auditfilter.c | 19 +++++++++++++------
kernel/auditsc.c | 2 +-
3 files changed, 17 insertions(+), 7 deletions(-)
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index 4d100c8..860df86 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -274,6 +274,9 @@
#define AUDIT_FILTERKEY 210
+/* Flag to indicate legacy AUDIT_LOGINUID unset usage */
+#define AUDIT_LOGINUID_LEGACY 0x80000000
+
#define AUDIT_NEGATE 0x80000000
/* These are the supported operators.
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 40ed981..39ce3e6 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -438,9 +438,13 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data
*data,
f->type = data->fields[i];
f->val = data->values[i];
+ err = audit_field_valid(entry, f);
+ if (err)
+ goto exit_free;
+
/* Support legacy tests for a valid loginuid */
if ((f->type == AUDIT_LOGINUID) && (f->val == AUDIT_UID_UNSET)) {
- f->type = AUDIT_LOGINUID_SET;
+ f->type = AUDIT_LOGINUID_SET | AUDIT_LOGINUID_LEGACY;
f->val = 0;
}
@@ -457,10 +461,6 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data
*data,
rcu_read_unlock();
}
- err = audit_field_valid(entry, f);
- if (err)
- goto exit_free;
-
err = -EINVAL;
switch (f->type) {
case AUDIT_LOGINUID:
@@ -630,6 +630,13 @@ static struct audit_rule_data *audit_krule_to_data(struct audit_krule
*krule)
data->buflen += data->values[i] =
audit_pack_string(&bufp, krule->filterkey);
break;
+ case AUDIT_LOGINUID_SET | AUDIT_LOGINUID_LEGACY:
+ if (!f->val) {
+ data->fields[i] = AUDIT_LOGINUID;
+ data->values[i] = AUDIT_UID_UNSET;
+ break;
+ }
+ /* fallthrough if set */
default:
data->values[i] = f->val;
}
@@ -1270,7 +1277,7 @@ static int audit_filter_user_rules(struct audit_krule *rule, int
type,
int result = 0;
u32 sid;
- switch (f->type) {
+ switch (f->type & ~AUDIT_LOGINUID_LEGACY) {
case AUDIT_PID:
pid = task_pid_nr(current);
result = audit_comparator(pid, f->op, f->val);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 8933572..ef25cbc 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -452,7 +452,7 @@ static int audit_filter_rules(struct task_struct *tsk,
int result = 0;
pid_t pid;
- switch (f->type) {
+ switch (f->type & ~AUDIT_LOGINUID_LEGACY) {
case AUDIT_PID:
pid = task_pid_nr(tsk);
result = audit_comparator(pid, f->op, f->val);
--
1.7.1