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
  ...

6 files changed, 55 insertions, 2 deletions

diff --git a/arch/arm/configs/hardening.config b/arch/arm/configs/hardening.config
new file mode 100644
index 000000000000..327349ce6377
--- /dev/null
+++ b/arch/arm/configs/hardening.config
@@ -0,0 +1,7 @@
+# Basic kernel hardening options (specific to arm)
+
+# Make sure PXN/PAN emulation is enabled.
+CONFIG_CPU_SW_DOMAIN_PAN=y
+
+# Dangerous; old interfaces and needless additional attack surface.
+# CONFIG_OABI_COMPAT is not set
diff --git a/arch/arm64/configs/hardening.config b/arch/arm64/configs/hardening.config
new file mode 100644
index 000000000000..b0e795208998
--- /dev/null
+++ b/arch/arm64/configs/hardening.config
@@ -0,0 +1,22 @@
+# Basic kernel hardening options (specific to arm64)
+
+# Make sure PAN emulation is enabled.
+CONFIG_ARM64_SW_TTBR0_PAN=y
+
+# Software Shadow Stack or PAC
+CONFIG_SHADOW_CALL_STACK=y
+
+# Pointer authentication (ARMv8.3 and later). If hardware actually supports
+# it, one can turn off CONFIG_STACKPROTECTOR_STRONG with this enabled.
+CONFIG_ARM64_PTR_AUTH=y
+CONFIG_ARM64_PTR_AUTH_KERNEL=y
+
+# Available in ARMv8.5 and later.
+CONFIG_ARM64_BTI=y
+CONFIG_ARM64_BTI_KERNEL=y
+CONFIG_ARM64_MTE=y
+CONFIG_KASAN_HW_TAGS=y
+CONFIG_ARM64_E0PD=y
+
+# Available in ARMv8.7 and later.
+CONFIG_ARM64_EPAN=y
diff --git a/arch/powerpc/configs/hardening.config b/arch/powerpc/configs/hardening.config
new file mode 100644
index 000000000000..4e9bba327e8f
--- /dev/null
+++ b/arch/powerpc/configs/hardening.config
@@ -0,0 +1,10 @@
+# PowerPC specific hardening options
+
+# Block kernel from unexpectedly reading userspace memory.
+CONFIG_PPC_KUAP=y
+
+# Attack surface reduction.
+# CONFIG_SCOM_DEBUGFS is not set
+
+# Disable internal kernel debugger.
+# CONFIG_XMON is not set
diff --git a/arch/sparc/kernel/cpumap.c b/arch/sparc/kernel/cpumap.c
index f07ea88a83af..8fcf2d8c6bd2 100644
--- a/arch/sparc/kernel/cpumap.c
+++ b/arch/sparc/kernel/cpumap.c
@@ -50,7 +50,7 @@ struct cpuinfo_tree {
 
 	/* Offsets into nodes[] for each level of the tree */
 	struct cpuinfo_level level[CPUINFO_LVL_MAX];
-	struct cpuinfo_node  nodes[];
+	struct cpuinfo_node  nodes[] __counted_by(total_nodes);
 };
 
 
diff --git a/arch/um/os-Linux/drivers/ethertap_user.c b/arch/um/os-Linux/drivers/ethertap_user.c
index 9483021d86dd..3363851a4ae8 100644
--- a/arch/um/os-Linux/drivers/ethertap_user.c
+++ b/arch/um/os-Linux/drivers/ethertap_user.c
@@ -105,7 +105,7 @@ static int etap_tramp(char *dev, char *gate, int control_me,
 	sprintf(data_fd_buf, "%d", data_remote);
 	sprintf(version_buf, "%d", UML_NET_VERSION);
 	if (gate != NULL) {
-		strncpy(gate_buf, gate, 15);
+		strscpy(gate_buf, gate, sizeof(gate_buf));
 		args = setup_args;
 	}
 	else args = nosetup_args;
diff --git a/arch/x86/configs/hardening.config b/arch/x86/configs/hardening.config
new file mode 100644
index 000000000000..7b497f3b7bc3
--- /dev/null
+++ b/arch/x86/configs/hardening.config
@@ -0,0 +1,14 @@
+# Basic kernel hardening options (specific to x86)
+
+# Modern libc no longer needs a fixed-position mapping in userspace, remove
+# it as a possible target.
+CONFIG_LEGACY_VSYSCALL_NONE=y
+
+# Enable chip-specific IOMMU support.
+CONFIG_INTEL_IOMMU=y
+CONFIG_INTEL_IOMMU_DEFAULT_ON=y
+CONFIG_INTEL_IOMMU_SVM=y
+CONFIG_AMD_IOMMU=y
+
+# Enable CET Shadow Stack for userspace.
+CONFIG_X86_USER_SHADOW_STACK=y