Commit-ID:  80d8ae86b36791a545ca28ddc95133ea59bba6e0
Gitweb:     http://git.kernel.org/tip/80d8ae86b36791a545ca28ddc95133ea59bba6e0
Author:     Eric Biggers <[email protected]>
AuthorDate: Sun, 24 Sep 2017 12:59:07 +0200
Committer:  Ingo Molnar <[email protected]>
CommitDate: Tue, 26 Sep 2017 09:43:46 +0200

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 <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Eric Biggers <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Kevin Hao <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Michael Halcrow <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Wanpeng Li <[email protected]>
Cc: Yu-cheng Yu <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
 arch/x86/kernel/fpu/xstate.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 2427aee..02591b96 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:

Reply via email to