Commit-ID: 1fc2b67b43d5001b92b3a002b988884ad0137e99 Gitweb: http://git.kernel.org/tip/1fc2b67b43d5001b92b3a002b988884ad0137e99 Author: Yu-cheng Yu <[email protected]> AuthorDate: Mon, 11 Jul 2016 09:18:54 -0700 Committer: Ingo Molnar <[email protected]> CommitDate: Mon, 11 Jul 2016 16:43:59 +0200
x86/fpu/xstate: Fix __fpu_restore_sig() for XSAVES When the kernel is using XSAVES compacted format, we cannot do __copy_from_user() from a signal frame, which has standard-format data. Fix it by using copyin_to_xsaves(), which converts between formats and filters out all supervisor states that we do not allow userspace to write. Signed-off-by: Yu-cheng Yu <[email protected]> Signed-off-by: Fenghua Yu <[email protected]> Reviewed-by: Dave Hansen <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ravi V Shankar <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/kernel/fpu/signal.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index 8aa96cb..9e231d8 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -323,8 +323,15 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size) */ fpu__drop(fpu); - if (__copy_from_user(&fpu->state.xsave, buf_fx, state_size) || - __copy_from_user(&env, buf, sizeof(env))) { + if (using_compacted_format()) { + err = copyin_to_xsaves(NULL, buf_fx, + &fpu->state.xsave); + } else { + err = __copy_from_user(&fpu->state.xsave, + buf_fx, state_size); + } + + if (err || __copy_from_user(&env, buf, sizeof(env))) { fpstate_init(&fpu->state); trace_x86_fpu_init_state(fpu); err = -1;
