Merge tag 'hardening-v7.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardening updates from Kees Cook:

 - Provide kmalloc_obj*-style API for devm_kmalloc()

 - Improve seq_buf API for saner C String handling with several bug
   fixes along the way (Kees Cook, Bill Wendling)

 - Overflow helper readability improvements (Bill Wendling)

 - Unexport native_write_cr4() (Dennis Chen)

 - um: fix CONFIG_GCOV for built-in code (Johannes Berg)

 - Improve stackinit test coverage (Justin Stitt)

 - KMSAN: fix memset() when using fortify-source, again (Arnd Bergmann)

 - lkdtm: use kmalloc() instead of __get_free_page (Mahad Ibrahim)

 - signalfd: don't dequeue the forced fatal signals (Oleg Nesterov)

 - Fix randstruct to recognize new container_of() behavior

 - coccinelle: kmalloc_obj: Convert multi-byte integral allocations too

 - Fix a couple remaining allocation return type mismatches

* tag 'hardening-v7.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (29 commits)
  overflow: Match arithmetic in both parts of __builtin_choose_expr
  lkdtm: Make UNSET_SMEP built-in-only and unexport native_write_cr4()
  extcon: realtek: Remove const from type_c_cfg allocation type
  coresight: cti: Add const to con_groups allocation type
  docs: core-api: Document the seq_buf API
  nvdimm: ndtest: Return the string length from flags_show()
  powerpc/papr_scm: Return the string length from the sysfs show functions
  seq_buf: Add seq_buf_init_append()
  bpf: Remove dead newline stripping from format_disasm_line()
  seq_buf: Add seq_buf_terminate()
  seq_buf: Add seq_buf_strlen()
  seq_buf: Clear what a writer did not claim when a seq_buf overflows
  seq_buf: Copy what fits when seq_buf_puts() and seq_buf_putmem() overflow
  scsi: lpfc: Print rx monitor records straight into the seq_buf
  seq_buf: Do not pop from an overflowed seq_buf
  seq_buf: Do not print an empty line from an overflowed seq_buf_do_printk()
  .get_maintainer.ignore: Add Kees Cook
  devres: Provide kmalloc_obj*-style API for devm_kmalloc
  mm: Move default_gfp() into gfp_types.h
  kunit/stackinit: Clean up XFAIL under instrumentation
  ...

2 files changed, 10 insertions, 10 deletions

diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
index 3eca2ef64aff..d82c47fb9f03 100644
--- a/drivers/misc/lkdtm/bugs.c
+++ b/drivers/misc/lkdtm/bugs.c
@@ -676,7 +676,7 @@ static void lkdtm_STACK_GUARD_PAGE_TRAILING(void)
 
 static void lkdtm_UNSET_SMEP(void)
 {
-#if IS_ENABLED(CONFIG_X86_64) && !IS_ENABLED(CONFIG_UML)
+#if IS_ENABLED(CONFIG_X86_64) && !IS_ENABLED(CONFIG_UML) && IS_BUILTIN(CONFIG_LKDTM)
 #define MOV_CR4_DEPTH	64
 	void (*direct_write_cr4)(unsigned long val);
 	unsigned char *insn;
@@ -737,7 +737,7 @@ static void lkdtm_UNSET_SMEP(void)
 		native_write_cr4(cr4);
 	}
 #else
-	pr_err("XFAIL: this test is x86_64-only\n");
+	pr_err("XFAIL: this test is x86_64-only and requires CONFIG_LKDTM=y\n");
 #endif
 }
 
diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c
index ededa32d6744..01bebcb33bd4 100644
--- a/drivers/misc/lkdtm/core.c
+++ b/drivers/misc/lkdtm/core.c
@@ -236,11 +236,11 @@ static ssize_t lkdtm_debugfs_entry(struct file *f,
 	if (count >= PAGE_SIZE)
 		return -EINVAL;
 
-	buf = (char *)__get_free_page(GFP_KERNEL);
+	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
 	if (copy_from_user(buf, user_buf, count)) {
-		free_page((unsigned long) buf);
+		kfree(buf);
 		return -EFAULT;
 	}
 	/* NULL-terminate and remove enter */
@@ -248,7 +248,7 @@ static ssize_t lkdtm_debugfs_entry(struct file *f,
 	strim(buf);
 
 	crashtype = find_crashtype(buf);
-	free_page((unsigned long)buf);
+	kfree(buf);
 
 	if (!crashtype)
 		return -EINVAL;
@@ -271,7 +271,7 @@ static ssize_t lkdtm_debugfs_read(struct file *f, char __user *user_buf,
 	ssize_t out;
 	char *buf;
 
-	buf = (char *)__get_free_page(GFP_KERNEL);
+	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 	if (buf == NULL)
 		return -ENOMEM;
 
@@ -290,7 +290,7 @@ static ssize_t lkdtm_debugfs_read(struct file *f, char __user *user_buf,
 
 	out = simple_read_from_buffer(user_buf, count, off,
 				      buf, n);
-	free_page((unsigned long) buf);
+	kfree(buf);
 
 	return out;
 }
@@ -313,11 +313,11 @@ static ssize_t direct_entry(struct file *f, const char __user *user_buf,
 	if (count < 1)
 		return -EINVAL;
 
-	buf = (char *)__get_free_page(GFP_KERNEL);
+	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
 	if (copy_from_user(buf, user_buf, count)) {
-		free_page((unsigned long) buf);
+		kfree(buf);
 		return -EFAULT;
 	}
 	/* NULL-terminate and remove enter */
@@ -325,7 +325,7 @@ static ssize_t direct_entry(struct file *f, const char __user *user_buf,
 	strim(buf);
 
 	crashtype = find_crashtype(buf);
-	free_page((unsigned long) buf);
+	kfree(buf);
 	if (!crashtype)
 		return -EINVAL;