[PATCH] audit: session ID should not set arch quick field pointer

[Richard Guy Briggs]

A bug was introduced in 8fae47705685fcaa75a1fe4c8c3e18300a702979
("audit: add support for session ID user filter")
See: https://github.com/linux-audit/audit-kernel/issues/4

When setting a session ID filter, the session ID filter field overwrote
the quick pointer reference to the arch field, potentially causing the
arch field to be misinterpreted.

Passes audit-testsuite.

Signed-off-by: Richard Guy Briggs <***@redhat.com>
---
kernel/auditfilter.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 4a1758a..739a6d2 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -496,7 +496,6 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
if (!gid_valid(f->gid))
goto exit_free;
break;
- case AUDIT_SESSIONID:
case AUDIT_ARCH:
entry->rule.arch_f = f;
break;

[Paul Moore]

Post by Richard Guy Briggs
A bug was introduced in 8fae47705685fcaa75a1fe4c8c3e18300a702979
("audit: add support for session ID user filter")
See: https://github.com/linux-audit/audit-kernel/issues/4
the quick pointer reference to the arch field, potentially causing the
arch field to be misinterpreted.
Passes audit-testsuite.
---
kernel/auditfilter.c | 1 -
1 file changed, 1 deletion(-)

Good catch. Merged.

Looking at the original patch and audit_field_valid(), I think we
should probably look into tightening up what constitutes "valid"
fields. For example, does it make sense to allow anything but
equal/not-equal when comparing AUDIT_SUBJ_TYPE? (note well: this is
just one example, there are many more)

* https://github.com/linux-audit/audit-kernel/issues/73

Post by Richard Guy Briggs
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 4a1758a..739a6d2 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -496,7 +496,6 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
if (!gid_valid(f->gid))
goto exit_free;
break;
entry->rule.arch_f = f;
break;
--
1.8.3.1