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
  ...

1 files changed, 6 insertions, 3 deletions

diff --git a/arch/um/drivers/virt-pci.c b/arch/um/drivers/virt-pci.c
index acb55b302b14..3ac220dafec4 100644
--- a/arch/um/drivers/virt-pci.c
+++ b/arch/um/drivers/virt-pci.c
@@ -97,7 +97,8 @@ static int um_pci_send_cmd(struct um_pci_device *dev,
 	}
 
 	buf = get_cpu_var(um_pci_msg_bufs);
-	memcpy(buf, cmd, cmd_size);
+	if (buf)
+		memcpy(buf, cmd, cmd_size);
 
 	if (posted) {
 		u8 *ncmd = kmalloc(cmd_size + extra_size, GFP_ATOMIC);
@@ -182,6 +183,7 @@ static unsigned long um_pci_cfgspace_read(void *priv, unsigned int offset,
 	struct um_pci_message_buffer *buf;
 	u8 *data;
 	unsigned long ret = ULONG_MAX;
+	size_t bytes = sizeof(buf->data);
 
 	if (!dev)
 		return ULONG_MAX;
@@ -189,7 +191,8 @@ static unsigned long um_pci_cfgspace_read(void *priv, unsigned int offset,
 	buf = get_cpu_var(um_pci_msg_bufs);
 	data = buf->data;
 
-	memset(buf->data, 0xff, sizeof(buf->data));
+	if (buf)
+		memset(data, 0xff, bytes);
 
 	switch (size) {
 	case 1:
@@ -204,7 +207,7 @@ static unsigned long um_pci_cfgspace_read(void *priv, unsigned int offset,
 		goto out;
 	}
 
-	if (um_pci_send_cmd(dev, &hdr, sizeof(hdr), NULL, 0, data, 8))
+	if (um_pci_send_cmd(dev, &hdr, sizeof(hdr), NULL, 0, data, bytes))
 		goto out;
 
 	switch (size) {