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 <zohar@xxxxxxxxxxxxx> Cc: Dmitry Kasatkin <dmitry.kasatkin@xxxxxxxxx> Cc: Paul Moore <paul@xxxxxxxxxxxxxx> Cc: James Morris <jmorris@xxxxxxxxx> Cc: "Serge E. Hallyn" <serge@xxxxxxxxxx> Cc: linux-integrity@xxxxxxxxxxxxxxx Cc: linux-security-module@xxxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- security/integrity/ima/ima_policy.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 69452b79686b..f69062617754 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -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; } -- 2.34.1
