[PATCH 1/2] audit: Allow auditing of proc/self/cmdline value
Audit records will now contain a new field, cmdline.
This is the value that is stored in proc/self/cmdline,
and is useful for debugging when processes are being run
via VM's. A primary example of this is Android, in which
package names are set in this location, and thread names
are set via PR_SET_NAME. The other benefit is this
is not limited to 16 bytes as COMM historically has.
Change-Id: I9bf0928a8aa249d22ecd55fa9cd27325dd394eb1
Signed-off-by: William Roberts <wroberts(a)tresys.com>
---
fs/proc/base.c | 2 +-
include/linux/proc_fs.h | 1 +
kernel/auditsc.c | 33 +++++++++++++++++++++++++++++++++
3 files changed, 35 insertions(+), 1 deletion(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 2f198da..25b73d3 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -209,7 +209,7 @@ struct mm_struct *mm_for_maps(struct task_struct *task)
return mm_access(task, PTRACE_MODE_READ);
}
-static int proc_pid_cmdline(struct task_struct *task, char * buffer)
+int proc_pid_cmdline(struct task_struct *task, char *buffer)
{
int res = 0;
unsigned int len;
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index 85c5073..d85ac14 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -118,6 +118,7 @@ struct pid_namespace;
extern int pid_ns_prepare_proc(struct pid_namespace *ns);
extern void pid_ns_release_proc(struct pid_namespace *ns);
+extern int proc_pid_cmdline(struct task_struct *task, char *buffer);
/*
* proc_tty.c
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 27ad9dd..45fd3d0 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -67,6 +67,7 @@
#include <linux/syscalls.h>
#include <linux/capability.h>
#include <linux/fs_struct.h>
+#include <linux/proc_fs.h>
#include "audit.h"
@@ -1153,6 +1154,37 @@ error_path:
EXPORT_SYMBOL(audit_log_task_context);
+static void audit_log_add_cmdline(struct audit_buffer *ab,
+ struct task_struct *tsk)
+{
+ int len;
+ unsigned long page;
+ char *msg = "(null)";
+
+ audit_log_format(ab, " cmdline=");
+
+ /* Get the process cmdline */
+ page = __get_free_page(GFP_TEMPORARY);
+ if (!page) {
+ audit_log_untrustedstring(ab, msg);
+ return;
+ }
+ len = proc_pid_cmdline(tsk, (char *)page);
+ if (len <= 0) {
+ free_page(page);
+ audit_log_untrustedstring(ab, msg);
+ return;
+ }
+ /*
+ * Ensure NULL terminated! Application could
+ * could be using setproctitle(3).
+ */
+ ((char *)page)[len-1] = '\0';
+ msg = (char *)page;
+ audit_log_untrustedstring(ab, msg);
+ free_page(page);
+}
+
static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
{
char name[sizeof(tsk->comm)];
@@ -1179,6 +1211,7 @@ static void audit_log_task_info(struct audit_buffer *ab, struct
task_struct *tsk
}
up_read(&mm->mmap_sem);
}
+ audit_log_add_cmdline(ab, tsk);
audit_log_task_context(ab);
}
--
1.7.9.5