There is no benefit from accepting and silently changing an invalid MXCSR
value supplied via ptrace(). Instead, return -EINVAL on invalid input.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210623121452.613614842@linutronix.de
if (ret)
return ret;
- /* Mask invalid MXCSR bits (for historical reasons). */
- newstate.mxcsr &= mxcsr_feature_mask;
+ /* Do not allow an invalid MXCSR value. */
+ if (newstate.mxcsr & ~mxcsr_feature_mask)
+ return -EINVAL;
fpu__prepare_write(fpu);