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().
diff --git a/fs/exec.c b/fs/exec.c
index fd774c7..c5c24f2 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1383,10 +1383,6 @@
if (retval)
return retval;
- retval = audit_bprm(bprm);
- if (retval)
- return retval;
-
/* Need to fetch pid before load_binary changes it */
old_pid = current->pid;
rcu_read_lock();
@@ -1408,6 +1404,7 @@
bprm->recursion_depth = depth;
if (retval >= 0) {
if (depth == 0) {
+ audit_bprm(bprm);
trace_sched_process_exec(current, old_pid, bprm);
ptrace_event(PTRACE_EVENT_EXEC, old_vpid);
}
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 08b38bf..a406419 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -238,11 +238,10 @@
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_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;
diff --git a/kernel/audit.h b/kernel/audit.h
index e7b94ab..b779642 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -199,7 +199,6 @@
} mmap;
struct {
int argc;
- struct mm_struct *mm;
} execve;
};
int fds[2];
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 425a893..dfc5d67 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1145,9 +1145,6 @@
const char __user *p;
char *buf;
- if (context->execve.mm != current->mm)
- return; /* execve failed, no additional info */
-
p = (const char __user *)current->mm->arg_start;
audit_log_format(*ab, "argc=%d", context->execve.argc);
@@ -2144,7 +2141,6 @@
context->type = AUDIT_EXECVE;
context->execve.argc = bprm->argc;
- context->execve.mm = bprm->mm;
}
