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-rw-r--r--arch/x86/ia32/sys_ia32.c4
-rw-r--r--include/linux/sched/task.h1
-rw-r--r--kernel/fork.c17
3 files changed, 20 insertions, 2 deletions
diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c
index 64a6c952091e..21790307121e 100644
--- a/arch/x86/ia32/sys_ia32.c
+++ b/arch/x86/ia32/sys_ia32.c
@@ -239,6 +239,7 @@ COMPAT_SYSCALL_DEFINE5(x86_clone, unsigned long, clone_flags,
{
struct kernel_clone_args args = {
.flags = (clone_flags & ~CSIGNAL),
+ .pidfd = parent_tidptr,
.child_tid = child_tidptr,
.parent_tid = parent_tidptr,
.exit_signal = (clone_flags & CSIGNAL),
@@ -246,5 +247,8 @@ COMPAT_SYSCALL_DEFINE5(x86_clone, unsigned long, clone_flags,
.tls = tls_val,
};
+ if (!legacy_clone_args_valid(&args))
+ return -EINVAL;
+
return _do_fork(&args);
}
diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index 109a0df5af39..0497091e40c1 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -89,6 +89,7 @@ extern void exit_files(struct task_struct *);
extern void exit_itimers(struct signal_struct *);
extern long _do_fork(struct kernel_clone_args *kargs);
+extern bool legacy_clone_args_valid(const struct kernel_clone_args *kargs);
extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
struct task_struct *fork_idle(int);
struct mm_struct *copy_init_mm(void);
diff --git a/kernel/fork.c b/kernel/fork.c
index 8f3e2d97d771..ef1e05a68827 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2406,6 +2406,16 @@ long _do_fork(struct kernel_clone_args *args)
return nr;
}
+bool legacy_clone_args_valid(const struct kernel_clone_args *kargs)
+{
+ /* clone(CLONE_PIDFD) uses parent_tidptr to return a pidfd */
+ if ((kargs->flags & CLONE_PIDFD) &&
+ (kargs->flags & CLONE_PARENT_SETTID))
+ return false;
+
+ return true;
+}
+
#ifndef CONFIG_HAVE_COPY_THREAD_TLS
/* For compatibility with architectures that call do_fork directly rather than
* using the syscall entry points below. */
@@ -2417,6 +2427,7 @@ long do_fork(unsigned long clone_flags,
{
struct kernel_clone_args args = {
.flags = (clone_flags & ~CSIGNAL),
+ .pidfd = parent_tidptr,
.child_tid = child_tidptr,
.parent_tid = parent_tidptr,
.exit_signal = (clone_flags & CSIGNAL),
@@ -2424,6 +2435,9 @@ long do_fork(unsigned long clone_flags,
.stack_size = stack_size,
};
+ if (!legacy_clone_args_valid(&args))
+ return -EINVAL;
+
return _do_fork(&args);
}
#endif
@@ -2505,8 +2519,7 @@ SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
.tls = tls,
};
- /* clone(CLONE_PIDFD) uses parent_tidptr to return a pidfd */
- if ((clone_flags & CLONE_PIDFD) && (clone_flags & CLONE_PARENT_SETTID))
+ if (!legacy_clone_args_valid(&args))
return -EINVAL;
return _do_fork(&args);