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-rw-r--r--kernel/fork.c32
1 files changed, 25 insertions, 7 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 0f2bbce..811ffba 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1565,9 +1565,11 @@ long do_fork(unsigned long clone_flags,
* Do some preliminary argument and permissions checking before we
* actually start allocating stuff
*/
- if (clone_flags & CLONE_NEWUSER) {
- if (clone_flags & CLONE_THREAD)
+ if (clone_flags & (CLONE_NEWUSER | CLONE_NEWPID)) {
+ if (clone_flags & (CLONE_THREAD|CLONE_PARENT))
return -EINVAL;
+ }
+ if (clone_flags & CLONE_NEWUSER) {
/* hopefully this check will go away when userns support is
* complete
*/
@@ -1692,7 +1694,8 @@ 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_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET|
+ CLONE_NEWPID))
return -EINVAL;
/*
* Not implemented, but pretend it works if there is nothing to
@@ -1763,15 +1766,30 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
int do_sysvsem = 0;
int err;
- err = check_unshare_flags(unshare_flags);
- if (err)
- goto bad_unshare_out;
-
+ /*
+ * If unsharing a pid namespace must also unshare the thread.
+ */
+ if (unshare_flags & CLONE_NEWPID)
+ unshare_flags |= CLONE_THREAD;
+ /*
+ * If unsharing a thread from a thread group, must also unshare vm.
+ */
+ if (unshare_flags & CLONE_THREAD)
+ unshare_flags |= CLONE_VM;
+ /*
+ * If unsharing vm, must also unshare signal handlers.
+ */
+ if (unshare_flags & CLONE_VM)
+ unshare_flags |= CLONE_SIGHAND;
/*
* If unsharing namespace, must also unshare filesystem information.
*/
if (unshare_flags & CLONE_NEWNS)
unshare_flags |= CLONE_FS;
+
+ err = check_unshare_flags(unshare_flags);
+ if (err)
+ goto bad_unshare_out;
/*
* CLONE_NEWIPC must also detach from the undolist: after switching
* to a new ipc namespace, the semaphore arrays from the old
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