audit: move audit_aux_data_execve contents into audit_context union

audit_bprm() was being called to add an AUDIT_EXECVE record to the audit
context every time search_binary_handler() was recursively called.  Only one
reference is necessary, so just update it.  Move the the contents of
audit_aux_data_execve into the union in audit_context, removing dependence on a
kmalloc along the way.

Reported-by: Oleg Nesterov <onestero@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 7b31bec..08b38bf 100644 (file)
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -209,7 +209,7 @@ static inline int audit_get_sessionid(struct task_struct *tsk)
 
 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_bprm(struct linux_binprm *bprm);
 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);
@@ -241,7 +241,7 @@ static inline void audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid
 static inline int audit_bprm(struct linux_binprm *bprm)
 {
        if (unlikely(!audit_dummy_context()))
-               return __audit_bprm(bprm);
+               __audit_bprm(bprm);
        return 0;
 }
 static inline int audit_socketcall(int nargs, unsigned long *args)

diff --git a/kernel/audit.h b/kernel/audit.h
index 123c9b7..e7b94ab 100644 (file)
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -197,6 +197,10 @@ struct audit_context {
                        int                     fd;
                        int                     flags;
                } mmap;
+               struct {
+                       int                     argc;
+                       struct mm_struct        *mm;
+               } execve;
        };
        int fds[2];
 

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 11078f3..425a893 100644 (file)
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -95,12 +95,6 @@ struct audit_aux_data {
 /* Number of target pids per aux struct. */
 #define AUDIT_AUX_PIDS 16
 
-struct audit_aux_data_execve {
-       struct audit_aux_data   d;
-       int argc;
-       struct mm_struct *mm;
-};
-
 struct audit_aux_data_pids {
        struct audit_aux_data   d;
        pid_t                   target_pid[AUDIT_AUX_PIDS];
@@ -1144,20 +1138,19 @@ static int audit_log_single_execve_arg(struct audit_context *context,
 }
 
 static void audit_log_execve_info(struct audit_context *context,
-                                 struct audit_buffer **ab,
-                                 struct audit_aux_data_execve *axi)
+                                 struct audit_buffer **ab)
 {
        int i, len;
        size_t len_sent = 0;
        const char __user *p;
        char *buf;
 
-       if (axi->mm != current->mm)
+       if (context->execve.mm != current->mm)
                return; /* execve failed, no additional info */
 
-       p = (const char __user *)axi->mm->arg_start;
+       p = (const char __user *)current->mm->arg_start;
 
-       audit_log_format(*ab, "argc=%d", axi->argc);
+       audit_log_format(*ab, "argc=%d", context->execve.argc);
 
        /*
         * we need some kernel buffer to hold the userspace args.  Just
@@ -1171,7 +1164,7 @@ static void audit_log_execve_info(struct audit_context *context,
                return;
        }
 
-       for (i = 0; i < axi->argc; i++) {
+       for (i = 0; i < context->execve.argc; i++) {
                len = audit_log_single_execve_arg(context, ab, i,
                                                  &len_sent, p, buf);
                if (len <= 0)
@@ -1274,6 +1267,9 @@ static void show_special(struct audit_context *context, int *call_panic)
                audit_log_format(ab, "fd=%d flags=0x%x", context->mmap.fd,
                                 context->mmap.flags);
                break; }
+       case AUDIT_EXECVE: {
+               audit_log_execve_info(context, &ab);
+               break; }
        }
        audit_log_end(ab);
 }
@@ -1320,11 +1316,6 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
 
                switch (aux->type) {
 
-               case AUDIT_EXECVE: {
-                       struct audit_aux_data_execve *axi = (void *)aux;
-                       audit_log_execve_info(context, &ab, axi);
-                       break; }
-
                case AUDIT_BPRM_FCAPS: {
                        struct audit_aux_data_bprm_fcaps *axs = (void *)aux;
                        audit_log_format(ab, "fver=%x", axs->fcap_ver);
@@ -2147,21 +2138,13 @@ void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mo
        context->ipc.has_perm = 1;
 }
 
-int __audit_bprm(struct linux_binprm *bprm)
+void __audit_bprm(struct linux_binprm *bprm)
 {
-       struct audit_aux_data_execve *ax;
        struct audit_context *context = current->audit_context;
 
-       ax = kmalloc(sizeof(*ax), GFP_KERNEL);
-       if (!ax)
-               return -ENOMEM;
-
-       ax->argc = bprm->argc;
-       ax->mm = bprm->mm;
-       ax->d.type = AUDIT_EXECVE;
-       ax->d.next = context->aux;
-       context->aux = (void *)ax;
-       return 0;
+       context->type = AUDIT_EXECVE;
+       context->execve.argc = bprm->argc;
+       context->execve.mm = bprm->mm;
 }