From: Peter Zijlstra <peterz@infradead.org>
Date: Tue, 14 Jun 2022 23:15:43 +0200
Subject: x86/vsyscall_emu/64: Don't use RET in vsyscall emulation
Git-commit: 15583e514eb16744b80be85dea0774ece153177d
Patch-mainline: v5.19-rc4
References: bsc#1199657 CVE-2022-29900 CVE-2022-29901

This is userspace code and doesn't play by the normal kernel rules.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/entry/vsyscall/vsyscall_emu_64.S | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/x86/entry/vsyscall/vsyscall_emu_64.S b/arch/x86/entry/vsyscall/vsyscall_emu_64.S
index 15e35159ebb6..ef2dd1827243 100644
--- a/arch/x86/entry/vsyscall/vsyscall_emu_64.S
+++ b/arch/x86/entry/vsyscall/vsyscall_emu_64.S
@@ -19,17 +19,20 @@ __vsyscall_page:
 
 	mov $__NR_gettimeofday, %rax
 	syscall
-	RET
+	ret
+	int3
 
 	.balign 1024, 0xcc
 	mov $__NR_time, %rax
 	syscall
-	RET
+	ret
+	int3
 
 	.balign 1024, 0xcc
 	mov $__NR_getcpu, %rax
 	syscall
-	RET
+	ret
+	int3
 
 	.balign 4096, 0xcc