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authorChristian Brauner <brauner@kernel.org>2026-02-26 14:51:00 +0100
committerChristian Brauner <brauner@kernel.org>2026-03-11 23:15:15 +0100
commit24baca56fafc33d4fb77cd9858a48c734183cb22 (patch)
tree8b819c9a038a0ef57c94547e49e525ed31959e72 /kernel
parent12ae2c81b21cfaa193db2faf035d495807edc3a7 (diff)
clone: add CLONE_NNP
Add a new clone3() flag CLONE_NNP that sets no_new_privs on the child process at clone time. This is analogous to prctl(PR_SET_NO_NEW_PRIVS) but applied at process creation rather than requiring a separate step after the child starts running. CLONE_NNP is rejected with CLONE_THREAD. It's conceptually a lot simpler if the whole thread-group is forced into NNP and not have single threads running around with NNP. Link: https://patch.msgid.link/20260226-work-pidfs-autoreap-v5-2-d148b984a989@kernel.org Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/fork.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 10549574fda6..736798e4005a 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2040,6 +2040,11 @@ __latent_entropy struct task_struct *copy_process(
if ((clone_flags & CLONE_PARENT) && current->signal->autoreap)
return ERR_PTR(-EINVAL);
+ if (clone_flags & CLONE_NNP) {
+ if (clone_flags & CLONE_THREAD)
+ return ERR_PTR(-EINVAL);
+ }
+
/*
* Force any signals received before this point to be delivered
* before the fork happens. Collect up signals sent to multiple
@@ -2424,6 +2429,9 @@ __latent_entropy struct task_struct *copy_process(
*/
copy_seccomp(p);
+ if (clone_flags & CLONE_NNP)
+ task_set_no_new_privs(p);
+
init_task_pid_links(p);
if (likely(p->pid)) {
ptrace_init_task(p, (clone_flags & CLONE_PTRACE) || trace);
@@ -2912,7 +2920,7 @@ static bool clone3_args_valid(struct kernel_clone_args *kargs)
/* Verify that no unknown flags are passed along. */
if (kargs->flags &
~(CLONE_LEGACY_FLAGS | CLONE_CLEAR_SIGHAND | CLONE_INTO_CGROUP |
- CLONE_AUTOREAP))
+ CLONE_AUTOREAP | CLONE_NNP))
return false;
/*