Merge tag 'hardening-v6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardening updates from Kees Cook:
 "One of the more voluminous set of changes is for adding the new
  __counted_by annotation[1] to gain run-time bounds checking of
  dynamically sized arrays with UBSan.

   - Add LKDTM test for stuck CPUs (Mark Rutland)

   - Improve LKDTM selftest behavior under UBSan (Ricardo Cañuelo)

   - Refactor more 1-element arrays into flexible arrays (Gustavo A. R.
     Silva)

   - Analyze and replace strlcpy and strncpy uses (Justin Stitt, Azeem
     Shaikh)

   - Convert group_info.usage to refcount_t (Elena Reshetova)

   - Add __counted_by annotations (Kees Cook, Gustavo A. R. Silva)

   - Add Kconfig fragment for basic hardening options (Kees Cook, Lukas
     Bulwahn)

   - Fix randstruct GCC plugin performance mode to stay in groups (Kees
     Cook)

   - Fix strtomem() compile-time check for small sources (Kees Cook)"

* tag 'hardening-v6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (56 commits)
  hwmon: (acpi_power_meter) replace open-coded kmemdup_nul
  reset: Annotate struct reset_control_array with __counted_by
  kexec: Annotate struct crash_mem with __counted_by
  virtio_console: Annotate struct port_buffer with __counted_by
  ima: Add __counted_by for struct modsig and use struct_size()
  MAINTAINERS: Include stackleak paths in hardening entry
  string: Adjust strtomem() logic to allow for smaller sources
  hardening: x86: drop reference to removed config AMD_IOMMU_V2
  randstruct: Fix gcc-plugin performance mode to stay in group
  mailbox: zynqmp: Annotate struct zynqmp_ipi_pdata with __counted_by
  drivers: thermal: tsens: Annotate struct tsens_priv with __counted_by
  irqchip/imx-intmux: Annotate struct intmux_data with __counted_by
  KVM: Annotate struct kvm_irq_routing_table with __counted_by
  virt: acrn: Annotate struct vm_memory_region_batch with __counted_by
  hwmon: Annotate struct gsc_hwmon_platform_data with __counted_by
  sparc: Annotate struct cpuinfo_tree with __counted_by
  isdn: kcapi: replace deprecated strncpy with strscpy_pad
  isdn: replace deprecated strncpy with strscpy
  NFS/flexfiles: Annotate struct nfs4_ff_layout_segment with __counted_by
  nfs41: Annotate struct nfs4_file_layout_dsaddr with __counted_by
  ...

1 files changed, 29 insertions, 1 deletions

diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
index c66cc05a68c4..b080eb2335eb 100644
--- a/drivers/misc/lkdtm/bugs.c
+++ b/drivers/misc/lkdtm/bugs.c
@@ -6,12 +6,14 @@
  * test source files.
  */
 #include "lkdtm.h"
+#include <linux/cpu.h>
 #include <linux/list.h>
 #include <linux/sched.h>
 #include <linux/sched/signal.h>
 #include <linux/sched/task_stack.h>
-#include <linux/uaccess.h>
 #include <linux/slab.h>
+#include <linux/stop_machine.h>
+#include <linux/uaccess.h>
 
 #if IS_ENABLED(CONFIG_X86_32) && !IS_ENABLED(CONFIG_UML)
 #include <asm/desc.h>
@@ -73,6 +75,31 @@ static void lkdtm_PANIC(void)
 	panic("dumptest");
 }
 
+static int panic_stop_irqoff_fn(void *arg)
+{
+	atomic_t *v = arg;
+
+	/*
+	 * As stop_machine() disables interrupts, all CPUs within this function
+	 * have interrupts disabled and cannot take a regular IPI.
+	 *
+	 * The last CPU which enters here will trigger a panic, and as all CPUs
+	 * cannot take a regular IPI, we'll only be able to stop secondaries if
+	 * smp_send_stop() or crash_smp_send_stop() uses an NMI.
+	 */
+	if (atomic_inc_return(v) == num_online_cpus())
+		panic("panic stop irqoff test");
+
+	for (;;)
+		cpu_relax();
+}
+
+static void lkdtm_PANIC_STOP_IRQOFF(void)
+{
+	atomic_t v = ATOMIC_INIT(0);
+	stop_machine(panic_stop_irqoff_fn, &v, cpu_online_mask);
+}
+
 static void lkdtm_BUG(void)
 {
 	BUG();
@@ -638,6 +665,7 @@ static noinline void lkdtm_CORRUPT_PAC(void)
 
 static struct crashtype crashtypes[] = {
 	CRASHTYPE(PANIC),
+	CRASHTYPE(PANIC_STOP_IRQOFF),
 	CRASHTYPE(BUG),
 	CRASHTYPE(WARNING),
 	CRASHTYPE(WARNING_MESSAGE),