From 93c2cdc975aab53c222472c5b96c2d41dbeb350c Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 24 Jun 2021 17:09:18 +0200
Subject: [PATCH] x86/fpu/xstate: Clear xstate header in
copy_xstate_to_uabi_buf() again
The change which made copy_xstate_to_uabi_buf() usable for
[x]fpregs_get() removed the zeroing of the header which means the
header, which is copied to user space later, contains except for the
xfeatures member, random stack content.
Add the memset() back to zero it before usage.
Fixes: eb6f51723f03 ("x86/fpu: Make copy_xstate_to_kernel() usable for [x]fpregs_get()")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/875yy3wb8h.ffs@nanos.tec.linutronix.de
---
arch/x86/kernel/fpu/xstate.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 21a10a66c4e45..c8def1b7f8fba 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -982,6 +982,7 @@ void copy_xstate_to_uabi_buf(struct membuf to, struct task_struct *tsk,
unsigned int zerofrom;
int i;
+ memset(&header, 0, sizeof(header));
header.xfeatures = xsave->header.xfeatures;
/* Mask out the feature bits depending on copy mode */