From 69f52573c24de9d2919f83e3b3b396a09118b7c4 Mon Sep 17 00:00:00 2001 From: Tiwei Bie Date: Wed, 19 Mar 2025 21:55:23 +0800 Subject: [PATCH] um: Prohibit the VM_CLONE flag in run_helper_thread() Directly creating helper threads with VM_CLONE using clone can compromise the thread safety of errno. Since all these helper threads have been converted to use os_run_helper_thread(), let's prevent using this flag in run_helper_thread(). Signed-off-by: Tiwei Bie Link: https://patch.msgid.link/20250319135523.97050-5-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg --- arch/um/os-Linux/helper.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c index df22cba24d82..89c2ad2a4e3a 100644 --- a/arch/um/os-Linux/helper.c +++ b/arch/um/os-Linux/helper.c @@ -122,6 +122,10 @@ int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags, unsigned long stack, sp; int pid, status, err; + /* To share memory space, use os_run_helper_thread() instead. */ + if (flags & CLONE_VM) + return -EINVAL; + stack = alloc_stack(0, __uml_cant_sleep()); if (stack == 0) return -ENOMEM; -- 2.25.1