Merge tag 'hardening-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull kernel hardening updates from Kees Cook:

 - Convert flexible array members, fix -Wstringop-overflow warnings, and
   fix KCFI function type mismatches that went ignored by maintainers
   (Gustavo A. R. Silva, Nathan Chancellor, Kees Cook)

 - Remove the remaining side-effect users of ksize() by converting
   dma-buf, btrfs, and coredump to using kmalloc_size_roundup(), add
   more __alloc_size attributes, and introduce full testing of all
   allocator functions. Finally remove the ksize() side-effect so that
   each allocation-aware checker can finally behave without exceptions

 - Introduce oops_limit (default 10,000) and warn_limit (default off) to
   provide greater granularity of control for panic_on_oops and
   panic_on_warn (Jann Horn, Kees Cook)

 - Introduce overflows_type() and castable_to_type() helpers for cleaner
   overflow checking

 - Improve code generation for strscpy() and update str*() kern-doc

 - Convert strscpy and sigphash tests to KUnit, and expand memcpy tests

 - Always use a non-NULL argument for prepare_kernel_cred()

 - Disable structleak plugin in FORTIFY KUnit test (Anders Roxell)

 - Adjust orphan linker section checking to respect CONFIG_WERROR (Xin
   Li)

 - Make sure siginfo is cleared for forced SIGKILL (haifeng.xu)

 - Fix um vs FORTIFY warnings for always-NULL arguments

* tag 'hardening-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (31 commits)
  ksmbd: replace one-element arrays with flexible-array members
  hpet: Replace one-element array with flexible-array member
  um: virt-pci: Avoid GCC non-NULL warning
  signal: Initialize the info in ksignal
  lib: fortify_kunit: build without structleak plugin
  panic: Expose "warn_count" to sysfs
  panic: Introduce warn_limit
  panic: Consolidate open-coded panic_on_warn checks
  exit: Allow oops_limit to be disabled
  exit: Expose "oops_count" to sysfs
  exit: Put an upper limit on how often we can oops
  panic: Separate sysctl logic from CONFIG_SMP
  mm/pgtable: Fix multiple -Wstringop-overflow warnings
  mm: Make ksize() a reporting-only function
  kunit/fortify: Validate __alloc_size attribute results
  drm/sti: Fix return type of sti_{dvo,hda,hdmi}_connector_mode_valid()
  drm/fsl-dcu: Fix return type of fsl_dcu_drm_connector_mode_valid()
  driver core: Add __alloc_size hint to devm allocators
  overflow: Introduce overflows_type() and castable_to_type()
  coredump: Proactively round up to kmalloc bucket size
  ...

4 files changed, 34 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-kernel-oops_count b/Documentation/ABI/testing/sysfs-kernel-oops_count
new file mode 100644
index 000000000000..156cca9dbc96
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-kernel-oops_count
@@ -0,0 +1,6 @@
+What:		/sys/kernel/oops_count
+Date:		November 2022
+KernelVersion:	6.2.0
+Contact:	Linux Kernel Hardening List <linux-hardening@vger.kernel.org>
+Description:
+		Shows how many times the system has Oopsed since last boot.
diff --git a/Documentation/ABI/testing/sysfs-kernel-warn_count b/Documentation/ABI/testing/sysfs-kernel-warn_count
new file mode 100644
index 000000000000..08f083d2fd51
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-kernel-warn_count
@@ -0,0 +1,6 @@
+What:		/sys/kernel/oops_count
+Date:		November 2022
+KernelVersion:	6.2.0
+Contact:	Linux Kernel Hardening List <linux-hardening@vger.kernel.org>
+Description:
+		Shows how many times the system has Warned since last boot.
diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index 39e7a2d46e1e..659d7bc47d7b 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -670,6 +670,15 @@ This is the default behavior.
 an oops event is detected.
 
 
+oops_limit
+==========
+
+Number of kernel oopses after which the kernel should panic when
+``panic_on_oops`` is not set. Setting this to 0 disables checking
+the count. Setting this to  1 has the same effect as setting
+``panic_on_oops=1``. The default value is 10000.
+
+
 osrelease, ostype & version
 ===========================
 
@@ -1526,6 +1535,16 @@ entry will default to 2 instead of 0.
 2 Unprivileged calls to ``bpf()`` are disabled
 = =============================================================
 
+
+warn_limit
+==========
+
+Number of kernel warnings after which the kernel should panic when
+``panic_on_warn`` is not set. Setting this to 0 disables checking
+the warning count. Setting this to 1 has the same effect as setting
+``panic_on_warn=1``. The default value is 0.
+
+
 watchdog
 ========
 
diff --git a/Documentation/core-api/kernel-api.rst b/Documentation/core-api/kernel-api.rst
index c9412eb85552..62f961610773 100644
--- a/Documentation/core-api/kernel-api.rst
+++ b/Documentation/core-api/kernel-api.rst
@@ -36,6 +36,9 @@ String Conversions
 String Manipulation
 -------------------
 
+.. kernel-doc:: include/linux/fortify-string.h
+   :internal:
+
 .. kernel-doc:: lib/string.c
    :export: