kernel: audit: beautify code, for extern function, better to check its parameters by itself
__audit_socketcall is an extern function.
better to check its parameters by itself.
also can return error code, when fail (find invalid parameters).
also use macro instead of real hard code number
also give related comments for it.
Signed-off-by: Chen Gang <gang.chen@asianux.com>
[eparis: fix the return value when !CONFIG_AUDIT]
Signed-off-by: Eric Paris <eparis@redhat.com>
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 37464c5..8f92e1d 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -84,6 +84,9 @@
#define AUDIT_TYPE_CHILD_DELETE 3 /* a child being deleted */
#define AUDIT_TYPE_CHILD_CREATE 4 /* a child being created */
+/* maximized args number that audit_socketcall can process */
+#define AUDITSC_ARGS 6
+
struct filename;
#ifdef CONFIG_AUDITSYSCALL
@@ -190,7 +193,7 @@
extern void __audit_ipc_obj(struct kern_ipc_perm *ipcp);
extern void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode);
extern int __audit_bprm(struct linux_binprm *bprm);
-extern void __audit_socketcall(int nargs, unsigned long *args);
+extern int __audit_socketcall(int nargs, unsigned long *args);
extern int __audit_sockaddr(int len, void *addr);
extern void __audit_fd_pair(int fd1, int fd2);
extern void __audit_mq_open(int oflag, umode_t mode, struct mq_attr *attr);
@@ -224,10 +227,11 @@
return __audit_bprm(bprm);
return 0;
}
-static inline void audit_socketcall(int nargs, unsigned long *args)
+static inline int audit_socketcall(int nargs, unsigned long *args)
{
if (unlikely(!audit_dummy_context()))
- __audit_socketcall(nargs, args);
+ return __audit_socketcall(nargs, args);
+ return 0;
}
static inline int audit_sockaddr(int len, void *addr)
{
@@ -354,8 +358,10 @@
{
return 0;
}
-static inline void audit_socketcall(int nargs, unsigned long *args)
-{ }
+static inline int audit_socketcall(int nargs, unsigned long *args)
+{
+ return 0;
+}
static inline void audit_fd_pair(int fd1, int fd2)
{ }
static inline int audit_sockaddr(int len, void *addr)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index b59ffb2..d57ad32 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -226,7 +226,7 @@
union {
struct {
int nargs;
- long args[6];
+ long args[AUDITSC_ARGS];
} socketcall;
struct {
kuid_t uid;
@@ -2491,17 +2491,20 @@
/**
* audit_socketcall - record audit data for sys_socketcall
- * @nargs: number of args
+ * @nargs: number of args, which should not be more than AUDITSC_ARGS.
* @args: args array
*
*/
-void __audit_socketcall(int nargs, unsigned long *args)
+int __audit_socketcall(int nargs, unsigned long *args)
{
struct audit_context *context = current->audit_context;
+ if (nargs <= 0 || nargs > AUDITSC_ARGS || !args)
+ return -EINVAL;
context->type = AUDIT_SOCKETCALL;
context->socketcall.nargs = nargs;
memcpy(context->socketcall.args, args, nargs * sizeof(unsigned long));
+ return 0;
}
/**
diff --git a/net/socket.c b/net/socket.c
index 2ca51c7..1bbc37b 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2436,7 +2436,7 @@
SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args)
{
- unsigned long a[6];
+ unsigned long a[AUDITSC_ARGS];
unsigned long a0, a1;
int err;
unsigned int len;
@@ -2452,7 +2452,9 @@
if (copy_from_user(a, args, len))
return -EFAULT;
- audit_socketcall(nargs[call] / sizeof(unsigned long), a);
+ err = audit_socketcall(nargs[call] / sizeof(unsigned long), a);
+ if (err)
+ return err;
a0 = a[0];
a1 = a[1];
