On Mon, Feb 12, 2018 at 7:29 AM, Richard Guy Briggs <rgb(a)redhat.com> wrote:
The arch_f pointer was added to the struct audit_krule in commit:
e54dc2431d740a79a6bd013babade99d71b1714f ("audit signal recipients")
This is only used on addition and deletion of rules which isn't time
critical and the arch field is likely to be one of the first fields,
easily found iterating over the field type. This isn't worth the
additional complexity and storage. Delete the field.
Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com>
---
include/linux/audit.h | 1 -
kernel/auditfilter.c | 12 ++++++++----
2 files changed, 8 insertions(+), 5 deletions(-)
I haven't decided if I like the removal of arch_f or not, but I think
I might know where your oops/panic is coming from, thoughts below ...
diff --git a/include/linux/audit.h b/include/linux/audit.h
index af410d9..64a3b0e 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -58,7 +58,6 @@ struct audit_krule {
u32 field_count;
char *filterkey; /* ties events to rules */
struct audit_field *fields;
- struct audit_field *arch_f; /* quick access to arch field */
struct audit_field *inode_f; /* quick access to an inode field */
struct audit_watch *watch; /* associated watch */
struct audit_tree *tree; /* associated watched tree */
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 739a6d2..3343d1c 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -220,7 +220,14 @@ static inline int audit_match_class_bits(int class, u32 *mask)
static int audit_match_signal(struct audit_entry *entry)
{
- struct audit_field *arch = entry->rule.arch_f;
+ int i;
+ struct audit_field *arch;
+
+ for (i = 0; i < entry->rule.field_count; i++)
+ if (entry->rule.fields[i].type == AUDIT_ARCH) {
+ arch = &entry->rule.fields[i];
+ break;
+ }
In the original code arch_f was initialized to NULL via the allocator
so the arch local variable was guaranteed to have a valid value or
NULL. Unfortunately, in your code if there is no AUDIT_ARCH field
arch could remain uninitialized which I believe could lead to the
oops/panic you are seeing.
if (!arch) {
/* When arch is unspecified, we must check both masks on biarch
@@ -496,9 +503,6 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data
*data,
if (!gid_valid(f->gid))
goto exit_free;
break;
- case AUDIT_ARCH:
- entry->rule.arch_f = f;
- break;
case AUDIT_SUBJ_USER:
case AUDIT_SUBJ_ROLE:
case AUDIT_SUBJ_TYPE:
--
1.8.3.1
--
paul moore
www.paul-moore.com