integrity: Annotate struct ima_rule_opt_list with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).

As found with Coccinelle[1], add __counted_by for struct ima_rule_opt_list. Additionally, since the element count member must be set before accessing the annotated flexible array member, move its initialization earlier.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc Mimi Zohar <[email protected]>

Cc Dmitry Kasatkin <[email protected]>

Cc Paul Moore <[email protected]>

Cc James Morris <[email protected]>

Cc "Serge E. Hallyn" <[email protected]>

Cc [email protected]

Cc [email protected]

Signed-off-by Kees Cook <[email protected]>

---
  security/integrity/ima/ima_policy.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

security/integrity/ima/ima_policy.c +2 -2

index 69452b79686b..f69062617754 100644
@@ -68,7 +68,7 @@ enum policy_rule_list { IMA_DEFAULT_POLICY = 1, IMA_CUSTOM_POLICY };
 
  struct ima_rule_opt_list {
  	size_t count;
-	char *items[];
+	char *items[] __counted_by(count);
  };
 
  /*

@@ -342,6 +342,7 @@ static struct ima_rule_opt_list *ima_alloc_rule_opt_list(const substring_t *src)
  		kfree(src_copy);
  		return ERR_PTR(-ENOMEM);
  	}
+	opt_list->count = count;
 
  	/*
  	 * strsep() has already replaced all instances of '|' with '\0',

@@ -357,7 +358,6 @@ static struct ima_rule_opt_list *ima_alloc_rule_opt_list(const substring_t *src)
  		opt_list->items[i] = cur;
  		cur = strchr(cur, '\0') + 1;
  	}
-	opt_list->count = count;
 
  	return opt_list;
  }

Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).

As found with Coccinelle[1], add __counted_by for struct ima_rule_opt_list. Additionally, since the element count member must be set before accessing the annotated flexible array member, move its initialization earlier.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc Mimi Zohar <[email protected]>

Cc Dmitry Kasatkin <[email protected]>

Cc Paul Moore <[email protected]>

Cc James Morris <[email protected]>

Cc "Serge E. Hallyn" <[email protected]>

Cc [email protected]

Cc [email protected]

Signed-off-by Kees Cook <[email protected]>

---
 security/integrity/ima/ima_policy.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

security/integrity/ima/ima_policy.c +2 -2

index 69452b79686b..f69062617754 100644
@@ -68,7 +68,7 @@ enum policy_rule_list { IMA_DEFAULT_POLICY = 1, IMA_CUSTOM_POLICY };
 
 struct ima_rule_opt_list {
 	size_t count;
-	char *items[];
+	char *items[] __counted_by(count);
 };
 
 /*

@@ -342,6 +342,7 @@ static struct ima_rule_opt_list *ima_alloc_rule_opt_list(const substring_t *src)
 		kfree(src_copy);
 		return ERR_PTR(-ENOMEM);
 	}
+	opt_list->count = count;
 
 	/*
 	 * strsep() has already replaced all instances of '|' with '\0',

@@ -357,7 +358,6 @@ static struct ima_rule_opt_list *ima_alloc_rule_opt_list(const substring_t *src)
 		opt_list->items[i] = cur;
 		cur = strchr(cur, '\0') + 1;
 	}
-	opt_list->count = count;
 
 	return opt_list;
 }

Signature · 1 line

2.34.1

Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).

As found with Coccinelle[1], add __counted_by for struct ima_rule_opt_list. Additionally, since the element count member must be set before accessing the annotated flexible array member, move its initialization earlier.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc Mimi Zohar <[email protected]>

Cc Dmitry Kasatkin <[email protected]>

Cc Paul Moore <[email protected]>

Cc James Morris <[email protected]>

Cc "Serge E. Hallyn" <[email protected]>

Cc [email protected]

Cc [email protected]

Signed-off-by Kees Cook <[email protected]>

Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).

As found with Coccinelle[1], add __counted_by for struct ima_rule_opt_list. Additionally, since the element count member must be set before accessing the annotated flexible array member, move its initialization earlier.

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