[134/181] mm/page_alloc.c: fix early params garbage value accesses

Commit Message

Andrew Morton Oct. 13, 2020, 11:55 p.m. UTC

From: Mateusz Nosek <[e-mail]>
Subject: mm/page_alloc.c: fix early params garbage value accesses

Previously in '__init early_init_on_alloc' and '__init early_init_on_free'
the return values from 'kstrtobool' were not handled properly.  That
caused potential garbage value read from variable 'bool_result'. 
Introduced patch fixes error handling.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Mateusz Nosek <[e-mail]>
Reviewed-by: Andrew Morton <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 mm/page_alloc.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

Patch

--- a/mm/page_alloc.c~mm-page_allocc-fix-early-params-garbage-value-accesses
+++ a/mm/page_alloc.c
@@ -156,16 +156,16 @@  static int __init early_init_on_alloc(ch
 	int ret;
 	bool bool_result;
 
-	if (!buf)
-		return -EINVAL;
 	ret = kstrtobool(buf, &bool_result);
+	if (ret)
+		return ret;
 	if (bool_result && page_poisoning_enabled())
 		pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, will take precedence over init_on_alloc\n");
 	if (bool_result)
 		static_branch_enable(&init_on_alloc);
 	else
 		static_branch_disable(&init_on_alloc);
-	return ret;
+	return 0;
 }
 early_param("init_on_alloc", early_init_on_alloc);
 
@@ -174,16 +174,16 @@  static int __init early_init_on_free(cha
 	int ret;
 	bool bool_result;
 
-	if (!buf)
-		return -EINVAL;
 	ret = kstrtobool(buf, &bool_result);
+	if (ret)
+		return ret;
 	if (bool_result && page_poisoning_enabled())
 		pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, will take precedence over init_on_free\n");
 	if (bool_result)
 		static_branch_enable(&init_on_free);
 	else
 		static_branch_disable(&init_on_free);
-	return ret;
+	return 0;
 }
 early_param("init_on_free", early_init_on_free);