git: 56d1afc72d6a - stable/13 - linux(4): Verify that higher 32bits of exit_signal in clone3 are unset.

The branch stable/13 has been updated by dchagin:

URL: https://cgit.FreeBSD.org/src/commit/?id=56d1afc72d6a6464d450cb24190610f2ba55ac8e

commit 56d1afc72d6a6464d450cb24190610f2ba55ac8e
Author:     Dmitry Chagin <dchagin@FreeBSD.org>
AuthorDate: 2021-08-12 08:56:51 +0000
Commit:     Dmitry Chagin <dchagin@FreeBSD.org>
CommitDate: 2022-06-17 19:33:32 +0000

    linux(4): Verify that higher 32bits of exit_signal in clone3 are unset.
    
    MFC after:              2 weeks
    
    (cherry picked from commit c2cc5345b88e98efb85ebc7318b8f92a8455345e)
---
 sys/compat/linux/linux_fork.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sys/compat/linux/linux_fork.c b/sys/compat/linux/linux_fork.c
index ba169ff98923..72e753db60d4 100644
--- a/sys/compat/linux/linux_fork.c
+++ b/sys/compat/linux/linux_fork.c
@@ -412,6 +412,10 @@ linux_clone3_args_valid(struct l_user_clone_args *uca)
 	if (uca->stack != 0 && uca->stack_size == 0)
 		return (EINVAL);
 
+	/* Verify that higher 32bits of exit_signal are unset. */
+	if ((uca->exit_signal & ~(uint64_t)LINUX_CSIGNAL) != 0)
+		return (EINVAL);
+
 	/* Verify that no unsupported flags are passed along. */
 	if ((uca->flags & LINUX_CLONE_NEWTIME) != 0) {
 		LINUX_RATELIMIT_MSG("unsupported clone3 option CLONE_NEWTIME");