Merge tag 'x86_urgent_for_v5.13_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:
"A first set of urgent fixes to the FPU/XSTATE handling mess^W code.
(There's a lot more in the pipe):

- Prevent corruption of the XSTATE buffer in signal handling by
validating what is being copied from userspace first.

- Invalidate other task's preserved FPU registers on XRSTOR failure
(#PF) because latter can still modify some of them.

- Restore the proper PKRU value in case userspace modified it

- Reset FPU state when signal restoring fails

Other:

- Map EFI boot services data memory as encrypted in a SEV guest so
that the guest can access it and actually boot properly

- Two SGX correctness fixes: proper resources freeing and a NUMA fix"

* tag 'x86_urgent_for_v5.13_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Avoid truncating memblocks for SGX memory
x86/sgx: Add missing xa_destroy() when virtual EPC is destroyed
x86/fpu: Reset state for all signal restore failures
x86/pkru: Write hardware init value to PKRU when xstate is init
x86/process: Check PF_KTHREAD and not current->mm for kernel threads
x86/fpu: Invalidate FPU state after a failed XRSTOR from a user buffer
x86/fpu: Prevent state corruption in __fpu__restore_sig()
x86/ioremap: Map EFI-reserved memory as encrypted for SEV

arch/x86/include/asm/fpu/internal.h

···
 	 * PKRU state is switched eagerly because it needs to be valid before we
 	 * return to userland e.g. for a copy_to_user() operation.
 	 */
-	if (current->mm) {
+	if (!(current->flags & PF_KTHREAD)) {
+		/*
+		 * If the PKRU bit in xsave.header.xfeatures is not set,
+		 * then the PKRU component was in init state, which means
+		 * XRSTOR will set PKRU to 0. If the bit is not set then
+		 * get_xsave_addr() will return NULL because the PKRU value
+		 * in memory is not valid. This means pkru_val has to be
+		 * set to 0 and not to init_pkru_value.
+		 */
 		pk = get_xsave_addr(&new_fpu->state.xsave, XFEATURE_PKRU);
-		if (pk)
-			pkru_val = pk->pkru;
+		pkru_val = pk ? pk->pkru : 0;
 	}
 	__write_pkru(pkru_val);
 }

arch/x86/kernel/cpu/sgx/virt.c

···
 		list_splice_tail(&secs_pages, &zombie_secs_pages);
 	mutex_unlock(&zombie_secs_pages_lock);
 
+	xa_destroy(&vepc->page_array);
 	kfree(vepc);
 
 	return 0;

arch/x86/kernel/fpu/signal.c

···
 		return 0;
 	}
 
-	if (!access_ok(buf, size))
-		return -EACCES;
+	if (!access_ok(buf, size)) {
+		ret = -EACCES;
+		goto out;
+	}
 
-	if (!static_cpu_has(X86_FEATURE_FPU))
-		return fpregs_soft_set(current, NULL,
-				       0, sizeof(struct user_i387_ia32_struct),
-				       NULL, buf) != 0;
+	if (!static_cpu_has(X86_FEATURE_FPU)) {
+		ret = fpregs_soft_set(current, NULL, 0,
+				      sizeof(struct user_i387_ia32_struct),
+				      NULL, buf);
+		goto out;
+	}
 
 	if (use_xsave()) {
 		struct _fpx_sw_bytes fx_sw_user;
···
 			fpregs_unlock();
 			return 0;
 		}
+
+		/*
+		 * The above did an FPU restore operation, restricted to
+		 * the user portion of the registers, and failed, but the
+		 * microcode might have modified the FPU registers
+		 * nevertheless.
+		 *
+		 * If the FPU registers do not belong to current, then
+		 * invalidate the FPU register state otherwise the task might
+		 * preempt current and return to user space with corrupted
+		 * FPU registers.
+		 *
+		 * In case current owns the FPU registers then no further
+		 * action is required. The fixup below will handle it
+		 * correctly.
+		 */
+		if (test_thread_flag(TIF_NEED_FPU_LOAD))
+			__cpu_invalidate_fpregs_state();
+
 		fpregs_unlock();
 	} else {
 		/*
···
 		 */
 		ret = __copy_from_user(&env, buf, sizeof(env));
 		if (ret)
-			goto err_out;
+			goto out;
 		envp = &env;
 	}
 
···
 	if (use_xsave() && !fx_only) {
 		u64 init_bv = xfeatures_mask_user() & ~user_xfeatures;
 
-		if (using_compacted_format()) {
-			ret = copy_user_to_xstate(&fpu->state.xsave, buf_fx);
-		} else {
-			ret = __copy_from_user(&fpu->state.xsave, buf_fx, state_size);
-
-			if (!ret && state_size > offsetof(struct xregs_state, header))
-				ret = validate_user_xstate_header(&fpu->state.xsave.header);
-		}
+		ret = copy_user_to_xstate(&fpu->state.xsave, buf_fx);
 		if (ret)
-			goto err_out;
+			goto out;
 
 		sanitize_restored_user_xstate(&fpu->state, envp, user_xfeatures,
 					      fx_only);
···
 		ret = __copy_from_user(&fpu->state.fxsave, buf_fx, state_size);
 		if (ret) {
 			ret = -EFAULT;
-			goto err_out;
+			goto out;
 		}
 
 		sanitize_restored_user_xstate(&fpu->state, envp, user_xfeatures,
···
 	} else {
 		ret = __copy_from_user(&fpu->state.fsave, buf_fx, state_size);
 		if (ret)
-			goto err_out;
+			goto out;
 
 		fpregs_lock();
 		ret = copy_kernel_to_fregs_err(&fpu->state.fsave);
···
 		fpregs_deactivate(fpu);
 	fpregs_unlock();
 
-err_out:
+out:
 	if (ret)
 		fpu__clear_user_states(fpu);
 	return ret;

arch/x86/mm/ioremap.c

···
 	if (!IS_ENABLED(CONFIG_EFI))
 		return;
 
-	if (efi_mem_type(addr) == EFI_RUNTIME_SERVICES_DATA)
+	if (efi_mem_type(addr) == EFI_RUNTIME_SERVICES_DATA ||
+	    (efi_mem_type(addr) == EFI_BOOT_SERVICES_DATA &&
+	     efi_mem_attributes(addr) & EFI_MEMORY_RUNTIME))
 		desc->flags |= IORES_MAP_ENCRYPTED;
 }
 

arch/x86/mm/numa.c

···
 
 		/* make sure all non-reserved blocks are inside the limits */
 		bi->start = max(bi->start, low);
-		bi->end = min(bi->end, high);
+
+		/* preserve info for non-RAM areas above 'max_pfn': */
+		if (bi->end > high) {
+			numa_add_memblk_to(bi->nid, high, bi->end,
+					   &numa_reserved_meminfo);
+			bi->end = high;
+		}
 
 		/* and there's no empty block */
 		if (bi->start >= bi->end)