From 80d8ae86b36791a545ca28ddc95133ea59bba6e0 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Sun, 24 Sep 2017 12:59:07 +0200 Subject: x86/fpu: Copy the full state_header in copy_kernel_to_xstate() This is in preparation to verify the full xstate header as supplied by user-space. Signed-off-by: Eric Biggers Cc: Andrew Morton Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: Dmitry Vyukov Cc: Eric Biggers Cc: Fenghua Yu Cc: Kees Cook Cc: Kevin Hao Cc: Linus Torvalds Cc: Michael Halcrow Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Rik van Riel Cc: Thomas Gleixner Cc: Wanpeng Li Cc: Yu-cheng Yu Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170924105913.9157-5-mingo@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/fpu/xstate.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 2427aeea33b5..02591b96bb25 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -1148,11 +1148,13 @@ int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf) int i; u64 xfeatures; u64 allowed_features; + struct xstate_header hdr; offset = offsetof(struct xregs_state, header); - size = sizeof(xfeatures); + size = sizeof(hdr); - memcpy(&xfeatures, kbuf + offset, size); + memcpy(&hdr, kbuf + offset, size); + xfeatures = hdr.xfeatures; /* * Reject if the user sets any disabled or supervisor features: -- cgit v1.2.3-59-g8ed1b