+ mm-page_allocc-fix-early-params-garbage-value-accesses.patch added to -mm tree

+ mm-page_allocc-fix-early-params-garbage-value-accesses.patch added to -mm tree

[akpm]

The patch titled
     Subject: mm/page_alloc.c: fix early params garbage value accesses
has been added to the -mm tree.  Its filename is
     mm-page_allocc-fix-early-params-garbage-value-accesses.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-page_allocc-fix-early-params-garbage-value-accesses.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-page_allocc-fix-early-params-garbage-value-accesses.patch

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------------------------------------------------------
From: Mateusz Nosek <mateusznosek0@gmail.com>
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/20200916214125.28271-1-mateusznosek0@gmail.com
Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

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

--- a/mm/page_alloc.c~mm-page_allocc-fix-early-params-garbage-value-accesses
+++ a/mm/page_alloc.c
@@ -155,16 +155,16 @@ 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);
 
@@ -173,16 +173,16 @@ 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);
 
_

Patches currently in -mm which might be from mateusznosek0@gmail.com are

mm-slabc-clean-code-by-removing-redundant-if-condition.patch
mm-page_allocc-clean-code-by-removing-unnecessary-initialization.patch
mm-page_allocc-micro-optimization-remove-unnecessary-branch.patch
mm-page_allocc-fix-early-params-garbage-value-accesses.patch
mm-compactionc-micro-optimization-remove-unnecessary-branch.patch