Subject: [RFC][v8][PATCH 7/10]: Check invalid clone flags
As pointed out by Oren Laadan, we want to ensure that unused bits in the
clone-flags remain unused and available for future. To ensure this, define
a mask of clone-flags and check the flags in the clone() system calls.
Changelog[v8]:
- New patch in set
Signed-off-by: Sukadev Bhattiprolu <[email protected]>
---
include/linux/sched.h | 10 ++++++++++
kernel/fork.c | 3 +++
2 files changed, 13 insertions(+)
Index: linux-2.6/include/linux/sched.h
===================================================================
--- linux-2.6.orig/include/linux/sched.h 2009-10-02 18:53:55.000000000
-0700
+++ linux-2.6/include/linux/sched.h 2009-10-02 19:58:21.000000000 -0700
@@ -29,6 +29,16 @@
#define CLONE_NEWNET 0x40000000 /* New network namespace */
#define CLONE_IO 0x80000000 /* Clone io context */
+#define VALID_CLONE_FLAGS (CSIGNAL | CLONE_VM | CLONE_FS | CLONE_FILES |\
+ CLONE_SIGHAND | CLONE_PTRACE | CLONE_VFORK |\
+ CLONE_PARENT | CLONE_THREAD | CLONE_NEWNS |\
+ CLONE_SYSVSEM | CLONE_SETTLS |\
+ CLONE_PARENT_SETTID | CLONE_CHILD_CLEARTID |\
+ CLONE_DETACHED | CLONE_UNTRACED |\
+ CLONE_CHILD_SETTID | CLONE_STOPPED |\
+ CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWUSER |\
+ CLONE_NEWPID | CLONE_NEWNET| CLONE_IO)
+
/*
* Scheduling policies
*/
Index: linux-2.6/kernel/fork.c
===================================================================
--- linux-2.6.orig/kernel/fork.c 2009-10-02 19:00:08.000000000 -0700
+++ linux-2.6/kernel/fork.c 2009-10-02 19:57:36.000000000 -0700
@@ -942,6 +942,9 @@ static struct task_struct *copy_process(
struct task_struct *p;
int cgroup_callbacks_done = 0;
+ if (clone_flags & ~VALID_CLONE_FLAGS)
+ return ERR_PTR(-EINVAL);
+
if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
return ERR_PTR(-EINVAL);
--
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