[PATCH V7 08/10] fork: audit on creation of new namespace(s) with clone and unshare

From: Richard Guy Briggs
Date: Tue May 12 2015 - 16:05:32 EST


When clone(2) is called to fork a new process or unshare(2) creating one or
more namespaces, audit the event to tie the new pid with the namespace IDs.

Added the macro CLONE_NEW_MASK_ALL to refer to all CLONE_NEW* flags.

Cleaned up check_unshare_flags() to make it more readable using this new macro.

Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
---
include/uapi/linux/sched.h | 6 ++++++
kernel/fork.c | 13 +++++++++----
2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/include/uapi/linux/sched.h b/include/uapi/linux/sched.h
index cc89dde..5f03ce9 100644
--- a/include/uapi/linux/sched.h
+++ b/include/uapi/linux/sched.h
@@ -28,6 +28,12 @@
#define CLONE_NEWUSER 0x10000000 /* New user namespace */
#define CLONE_NEWPID 0x20000000 /* New pid namespace */
#define CLONE_NEWNET 0x40000000 /* New network namespace */
+#define CLONE_NEW_MASK_ALL (CLONE_NEWNS \
+ | CLONE_NEWUTS \
+ | CLONE_NEWIPC \
+ | CLONE_NEWUSER \
+ | CLONE_NEWPID \
+ | CLONE_NEWNET) /* mask of all namespace type flags */
#define CLONE_IO 0x80000000 /* Clone io context */

/*
diff --git a/kernel/fork.c b/kernel/fork.c
index cf65139..c09c5df 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1680,6 +1680,9 @@ long do_fork(unsigned long clone_flags,
get_task_struct(p);
}

+ if (unlikely(clone_flags & CLONE_NEW_MASK_ALL))
+ audit_log_ns_info(p);
+
wake_up_new_task(p);

/* forking complete and child started to run, tell ptracer */
@@ -1802,10 +1805,9 @@ void __init proc_caches_init(void)
*/
static int check_unshare_flags(unsigned long unshare_flags)
{
- if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
- CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|
- CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET|
- CLONE_NEWUSER|CLONE_NEWPID))
+ if (unshare_flags & ~(CLONE_THREAD | CLONE_FS | CLONE_SIGHAND |
+ CLONE_VM | CLONE_FILES | CLONE_SYSVSEM |
+ CLONE_NEW_MASK_ALL))
return -EINVAL;
/*
* Not implemented, but pretend it works if there is nothing to
@@ -1964,6 +1966,9 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
commit_creds(new_cred);
new_cred = NULL;
}
+
+ if (unshare_flags & CLONE_NEW_MASK_ALL)
+ audit_log_ns_info(current);
}

bad_unshare_cleanup_cred:
--
1.7.1

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