audit: call audit_bprm() only once to add AUDIT_EXECVE information

Move the audit_bprm() call from search_binary_handler() to exec_binprm().  This
allows us to get rid of the mm member of struct audit_aux_data_execve since
bprm->mm will equal current->mm.

This also mitigates the issue that ->argc could be modified by the
load_binary() call in search_binary_handler().

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.

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>
---
This patch is against 3.11, but was developed on Oleg's post-3.11 patches that
introduce exec_binprm().

1 files changed, 3 insertions, 6 deletions

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 08b38bf13eb..a40641954c2 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -238,11 +238,10 @@ static inline void audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid
 	if (unlikely(!audit_dummy_context()))
 		__audit_ipc_set_perm(qbytes, uid, gid, mode);
 }
-static inline int audit_bprm(struct linux_binprm *bprm)
+static inline void audit_bprm(struct linux_binprm *bprm)
 {
 	if (unlikely(!audit_dummy_context()))
 		__audit_bprm(bprm);
-	return 0;
 }
 static inline int audit_socketcall(int nargs, unsigned long *args)
 {
@@ -369,10 +368,8 @@ static inline void audit_ipc_obj(struct kern_ipc_perm *ipcp)
 static inline void audit_ipc_set_perm(unsigned long qbytes, uid_t uid,
 					gid_t gid, umode_t mode)
 { }
-static inline int audit_bprm(struct linux_binprm *bprm)
-{
-	return 0;
-}
+static inline void audit_bprm(struct linux_binprm *bprm)
+{ }
 static inline int audit_socketcall(int nargs, unsigned long *args)
 {
 	return 0;