[patch 4/8] x86/fpu: Limit xstate copy size in xstateregs_set()

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@linutronix.de Cc: stable@vger.kernel.org --- 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;