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
  ...

6 files changed, 23 insertions, 16 deletions

diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index 8c63f0a26f56b0..2ef651a78fa2a9 100644
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -124,7 +124,7 @@ LDFLAGS_vmlinux += --no-undefined
 LDFLAGS_vmlinux += -X
 # Report orphan sections
 ifdef CONFIG_LD_ORPHAN_WARN
-LDFLAGS_vmlinux += --orphan-handling=warn
+LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
 endif
 # Next argument is a linker script
 LDFLAGS_vmlinux += -T
diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile
index 619e2dc7ee14cc..beaf9586338f5c 100644
--- a/arch/arm64/kernel/vdso/Makefile
+++ b/arch/arm64/kernel/vdso/Makefile
@@ -27,7 +27,7 @@ ldflags-y := -shared -soname=linux-vdso.so.1 --hash-style=sysv	\
 	     -Bsymbolic --build-id=sha1 -n $(btildflags-y)
 
 ifdef CONFIG_LD_ORPHAN_WARN
-  ldflags-y += --orphan-handling=warn
+  ldflags-y += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
 endif
 
 ldflags-y += -T
diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile
index 36c8f66cad251a..f59bd1a4ead6b4 100644
--- a/arch/arm64/kernel/vdso32/Makefile
+++ b/arch/arm64/kernel/vdso32/Makefile
@@ -104,7 +104,7 @@ VDSO_AFLAGS += -D__ASSEMBLY__
 VDSO_LDFLAGS += -Bsymbolic --no-undefined -soname=linux-vdso.so.1
 VDSO_LDFLAGS += -z max-page-size=4096 -z common-page-size=4096
 VDSO_LDFLAGS += -shared --hash-style=sysv --build-id=sha1
-VDSO_LDFLAGS += --orphan-handling=warn
+VDSO_LDFLAGS += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
 
 
 # Borrow vdsomunge.c from the arm vDSO
diff --git a/arch/um/drivers/virt-pci.c b/arch/um/drivers/virt-pci.c
index acb55b302b14c3..3ac220dafec4a5 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) {
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 3dc5db651dd0a1..1acff356d97a9c 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -68,7 +68,7 @@ KBUILD_LDFLAGS += $(call ld-option,--no-ld-generated-unwind-info)
 # address by the bootloader.
 LDFLAGS_vmlinux := -pie $(call ld-option, --no-dynamic-linker)
 ifdef CONFIG_LD_ORPHAN_WARN
-LDFLAGS_vmlinux += --orphan-handling=warn
+LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
 endif
 LDFLAGS_vmlinux += -z noexecstack
 ifeq ($(CONFIG_LD_IS_BFD),y)
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 8525f2876fb409..e4f499eb0f295b 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -299,9 +299,6 @@ static void pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd, pmd_t *pmds[])
 	pud_t *pud;
 	int i;
 
-	if (PREALLOCATED_PMDS == 0) /* Work around gcc-3.4.x bug */
-		return;
-
 	p4d = p4d_offset(pgd, 0);
 	pud = pud_offset(p4d, 0);
 
@@ -434,10 +431,12 @@ pgd_t *pgd_alloc(struct mm_struct *mm)
 
 	mm->pgd = pgd;
 
-	if (preallocate_pmds(mm, pmds, PREALLOCATED_PMDS) != 0)
+	if (sizeof(pmds) != 0 &&
+			preallocate_pmds(mm, pmds, PREALLOCATED_PMDS) != 0)
 		goto out_free_pgd;
 
-	if (preallocate_pmds(mm, u_pmds, PREALLOCATED_USER_PMDS) != 0)
+	if (sizeof(u_pmds) != 0 &&
+			preallocate_pmds(mm, u_pmds, PREALLOCATED_USER_PMDS) != 0)
 		goto out_free_pmds;
 
 	if (paravirt_pgd_alloc(mm) != 0)
@@ -451,17 +450,22 @@ pgd_t *pgd_alloc(struct mm_struct *mm)
 	spin_lock(&pgd_lock);
 
 	pgd_ctor(mm, pgd);
-	pgd_prepopulate_pmd(mm, pgd, pmds);
-	pgd_prepopulate_user_pmd(mm, pgd, u_pmds);
+	if (sizeof(pmds) != 0)
+		pgd_prepopulate_pmd(mm, pgd, pmds);
+
+	if (sizeof(u_pmds) != 0)
+		pgd_prepopulate_user_pmd(mm, pgd, u_pmds);
 
 	spin_unlock(&pgd_lock);
 
 	return pgd;
 
 out_free_user_pmds:
-	free_pmds(mm, u_pmds, PREALLOCATED_USER_PMDS);
+	if (sizeof(u_pmds) != 0)
+		free_pmds(mm, u_pmds, PREALLOCATED_USER_PMDS);
 out_free_pmds:
-	free_pmds(mm, pmds, PREALLOCATED_PMDS);
+	if (sizeof(pmds) != 0)
+		free_pmds(mm, pmds, PREALLOCATED_PMDS);
 out_free_pgd:
 	_pgd_free(pgd);
 out: