audit: fix potential null dereference 'context->module.name' (b305f7ed) · Commits · 戴 / test

The variable 'context->module.name' may be null pointer when kmalloc return null, so it's better to check it before using to avoid null dereference. Another one more thing this patch does is using kstrdup instead of (kmalloc + strcpy), and signal a lost record via audit_log_lost. Cc: stable@vger.kernel.org # 4.11 Signed-off-by:

Yi Wang <wang.yi59@zte.com.cn> Reviewed-by:

Jiang Biao <jiang.biao2@zte.com.cn> Reviewed-by:

Richard Guy Briggs <rgb@redhat.com> Signed-off-by:

Paul Moore <paul@paul-moore.com>

kernel/auditsc.c

+9 −4

Original line number	Diff line number	Diff line
		@@ -1279,8 +1279,12 @@ static void show_special(struct audit_context context, int call_panic)
		break;
		case AUDIT_KERN_MODULE:
		audit_log_format(ab, "name=");
		if (context->module.name) {
		audit_log_untrustedstring(ab, context->module.name);
		kfree(context->module.name);
		} else
		audit_log_format(ab, "(null)");

		break;
		}
		audit_log_end(ab);
		@@ -2411,8 +2415,9 @@ void __audit_log_kern_module(char *name)
		{
		struct audit_context *context = audit_context();

		context->module.name = kmalloc(strlen(name) + 1, GFP_KERNEL);
		strcpy(context->module.name, name);
		context->module.name = kstrdup(name, GFP_KERNEL);
		if (!context->module.name)
		audit_log_lost("out of memory in __audit_log_kern_module");
		context->type = AUDIT_KERN_MODULE;
		}

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