From 93c2cdc975aab53c222472c5b96c2d41dbeb350c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner 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 Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov 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 21a10a6..c8def1b 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 */ -- 2.7.4