Standalone audit records have the timestamp and serial number generated
on the fly and as such are unique, making them standalone. This new
function audit_alloc_local() generates a local audit context that will
be used only for a standalone record and its auxiliary record(s). The
context is discarded immediately after the local associated records are
produced.
Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
Acked-by: Serge Hallyn <serge@xxxxxxxxxx>
Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
Reviewed-by: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
---
include/linux/audit.h | 8 ++++++++
kernel/audit.h | 1 +
kernel/auditsc.c | 35 ++++++++++++++++++++++++++++++-----
3 files changed, 39 insertions(+), 5 deletions(-)
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 7b640c4da4ee..e849058cb662 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -329,6 +329,8 @@ static inline int audit_signal_info(int sig, struct task_struct *t)
/* These are defined in auditsc.c */
/* Public API */
+extern struct audit_context *audit_alloc_local(gfp_t gfpflags);
+extern void audit_free_context(struct audit_context *context);
extern void __audit_syscall_entry(int major, unsigned long a0, unsigned long a1,
unsigned long a2, unsigned long a3);
extern void __audit_syscall_exit(int ret_success, long ret_value);
@@ -591,6 +593,12 @@ static inline void audit_ntp_log(const struct audit_ntp_data *ad)
extern int audit_n_rules;
extern int audit_signals;
#else /* CONFIG_AUDITSYSCALL */
+static inline struct audit_context *audit_alloc_local(gfp_t gfpflags)
+{
+ return NULL;
+}
+static inline void audit_free_context(struct audit_context *context)
+{ }
static inline void audit_syscall_entry(int major, unsigned long a0,
unsigned long a1, unsigned long a2,
unsigned long a3)
diff --git a/kernel/audit.h b/kernel/audit.h
index c9a118716ced..1bba13bdffd0 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -98,6 +98,7 @@ struct audit_proctitle {
struct audit_context {
int dummy; /* must be the first element */
int in_syscall; /* 1 if task is in a syscall */
+ bool local; /* local context needed */
enum audit_state state, current_state;
unsigned int serial; /* serial number for record */
int major; /* syscall number */
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index ac438fcff807..3138c88887c7 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -890,11 +890,13 @@ static inline void audit_free_aux(struct audit_context *context)
}
}
-static inline struct audit_context *audit_alloc_context(enum audit_state state)
+static inline struct audit_context *audit_alloc_context(enum audit_state state,
+ gfp_t gfpflags)
{
struct audit_context *context;
- context = kzalloc(sizeof(*context), GFP_KERNEL);
+ /* We can be called in atomic context via audit_tg() */
+ context = kzalloc(sizeof(*context), gfpflags);
if (!context)
return NULL;
context->state = state;
@@ -930,7 +932,8 @@ int audit_alloc_syscall(struct task_struct *tsk)
return 0;
}
- if (!(context = audit_alloc_context(state))) {
+ context = audit_alloc_context(state, GFP_KERNEL);
+ if (!context) {
kfree(key);
audit_log_lost("out of memory in audit_alloc_syscall");
return -ENOMEM;
@@ -942,8 +945,29 @@ int audit_alloc_syscall(struct task_struct *tsk)
return 0;
}
-static inline void audit_free_context(struct audit_context *context)
+struct audit_context *audit_alloc_local(gfp_t gfpflags)
{
+ struct audit_context *context = NULL;
+
+ if (!audit_ever_enabled)
+ goto out; /* Return if not auditing. */
+ context = audit_alloc_context(AUDIT_RECORD_CONTEXT, gfpflags);
+ if (!context) {
+ audit_log_lost("out of memory in audit_alloc_local");
+ goto out;
+ }
+ context->serial = audit_serial();
+ ktime_get_coarse_real_ts64(&context->ctime);
+ context->local = true;
+out:
+ return context;
+}
+EXPORT_SYMBOL(audit_alloc_local);
+
+void audit_free_context(struct audit_context *context)
+{
+ if (!context)
+ return;
audit_free_module(context);
audit_free_names(context);
unroll_tree_refs(context, NULL, 0);
@@ -954,6 +978,7 @@ static inline void audit_free_context(struct audit_context *context)
audit_proctitle_free(context);
kfree(context);
}
+EXPORT_SYMBOL(audit_free_context);
static int audit_log_pid_context(struct audit_context *context, pid_t pid,
kuid_t auid, kuid_t uid, unsigned int sessionid,
@@ -2182,7 +2207,7 @@ void __audit_inode_child(struct inode *parent,
int auditsc_get_stamp(struct audit_context *ctx,
struct timespec64 *t, unsigned int *serial)
{
- if (!ctx->in_syscall)
+ if (!ctx->in_syscall && !ctx->local)
return 0;
if (!ctx->serial)
ctx->serial = audit_serial();
--
1.8.3.1
