[PATCH] x86/fpu/xstate: Clear xstate header in copy_xstate_to_uabi_buf() again

[Thomas Gleixner]

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@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
Changelog summary: I'm a moron.
---
 arch/x86/kernel/fpu/xstate.c |    1 +
 1 file changed, 1 insertion(+)

--- 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 memb
 	unsigned int zerofrom;
 	int i;
 
+	memset(&header, 0, sizeof(header));
 	header.xfeatures = xsave->header.xfeatures;
 
 	/* Mask out the feature bits depending on copy mode */