On Wed, Jun 02, 2021 at 11:55:47AM +0200, Thomas Gleixner wrote:
> If the count argument is larger than the xstate size, this will happily
> copy beyond the end of xstate.
>
> Fixes: 91c3dba7dbc1 ("x86/fpu/xstate: Fix PTRACE frames for XSAVES")
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> arch/x86/kernel/fpu/regset.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- a/arch/x86/kernel/fpu/regset.c
> +++ b/arch/x86/kernel/fpu/regset.c
> @@ -117,7 +117,7 @@ int xstateregs_set(struct task_struct *t
> /*
> * A whole standard-format XSAVE buffer is needed:
> */
> - if ((pos != 0) || (count < fpu_user_xstate_size))
> + if (pos != 0 || count != fpu_user_xstate_size)
> return -EFAULT;
>
> xsave = &fpu->state.xsave;
Looking at this one, I guess it and all the CC:stable ones should be at
the beginning of the set so that they go to Linus now...
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
