From patchwork Fri Nov 15 13:35:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Christian_G=C3=B6ttsche?= X-Patchwork-Id: 13876253 Received: from server02.seltendoof.de (server02.seltendoof.de [168.119.48.163]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9C0D71CDFC1; Fri, 15 Nov 2024 13:36:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=168.119.48.163 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731677817; cv=none; b=PccLF5fAWTA03qnpk2axEblUzDy3tTQ/zCsDkUeU0xPB46SrNXhaCyFnW5NldU95vT/YiSTbLPxORCheNvT9GipojPik0tpCqsbbT0l9t8aWQemUvAT68LzRk5vfkANMmJIHZvs3X7OLAg5x5QY/Ww9P/M4402C3aabyo9UZJ8I= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731677817; c=relaxed/simple; bh=ouHDODVJurRyJEOkOhCj9pVvwAvdaE9uDibnZlcGZN0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=N281GkLV1LOVNeobR0xPZnTKNH0+cLn7168MJGPJQLZQrPnL7eZwzCFLFoHs27v5pH4F2vidJBXHAjxw3ZBf50mTnAnG2JIlD5lgBRGXdGgHE560gvDV8nUQwQm9RqydRMPJLIly0LyweKUtDpRlwasTalZGNFW4LMMoImrkVJo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=seltendoof.de; spf=pass smtp.mailfrom=seltendoof.de; dkim=pass (2048-bit key) header.d=seltendoof.de header.i=@seltendoof.de header.b=mZ0E4jus; arc=none smtp.client-ip=168.119.48.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=seltendoof.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=seltendoof.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=seltendoof.de header.i=@seltendoof.de header.b="mZ0E4jus" From: =?utf-8?q?Christian_G=C3=B6ttsche?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=seltendoof.de; s=2023072701; t=1731677812; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=R2g5Wk+CWFl28MX4lhzXMKz3Oz2ct6jAzT7+Bkx0DJg=; b=mZ0E4jus303HZmXIXmo5nMnPfRfDAYpDKy3jlgD+9mdaySPZqngn9u/9AppSwmLg+3wRuI aBpvcGL5bqDrgu3p7VHIjPz4TQrbITWCgWQY0WpuF390xZ4bPhoYk142VSJ+hb36EfIWKD Oo1ArTkrVdSH5TFv5lSW9AQoDrbg45+Z/4mrWs2emkO7r5E8HBKDm1v3vYU4LtS2FQyHbv c8M5QBaFcffmqG3oDyCj9abvMXckp5Kn8SnUboo8cEPZAHYeA00+BIthHl2K79ArTgxJq+ L7pSAolgEfZmIFhoNxsnNIci20Gl86oFh1TyKSVGgb1nO2a+ru2PXUGYDHb/MA== To: selinux@vger.kernel.org Cc: =?utf-8?q?Christian_G=C3=B6ttsche?= , Paul Moore , Stephen Smalley , Ondrej Mosnacek , linux-kernel@vger.kernel.org Subject: [RFC PATCH 05/22] selinux: avoid nontransitive comparison Date: Fri, 15 Nov 2024 14:35:24 +0100 Message-ID: <20241115133619.114393-5-cgoettsche@seltendoof.de> In-Reply-To: <20241115133619.114393-1-cgoettsche@seltendoof.de> References: <20241115133619.114393-1-cgoettsche@seltendoof.de> Reply-To: cgzones@googlemail.com Precedence: bulk X-Mailing-List: selinux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Christian Göttsche Avoid using nontransitive comparison to prevent unexpected sorting results due to (well-defined) overflows. See https://www.qualys.com/2024/01/30/qsort.txt for a related issue in glibc's qsort(3). Signed-off-by: Christian Göttsche --- security/selinux/ss/policydb.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index 383f3ae82a73..d04d9ada3835 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -37,6 +37,8 @@ #include "mls.h" #include "services.h" +#define spaceship_cmp(a, b) (((a) > (b)) - ((a) < (b))) + #ifdef CONFIG_SECURITY_SELINUX_DEBUG /* clang-format off */ static const char *const symtab_name[SYM_NUM] = { @@ -421,11 +423,11 @@ static int filenametr_cmp(const void *k1, const void *k2) const struct filename_trans_key *ft2 = k2; int v; - v = ft1->ttype - ft2->ttype; + v = spaceship_cmp(ft1->ttype, ft2->ttype); if (v) return v; - v = ft1->tclass - ft2->tclass; + v = spaceship_cmp(ft1->tclass, ft2->tclass); if (v) return v; @@ -456,15 +458,15 @@ static int rangetr_cmp(const void *k1, const void *k2) const struct range_trans *key1 = k1, *key2 = k2; int v; - v = key1->source_type - key2->source_type; + v = spaceship_cmp(key1->source_type, key2->source_type); if (v) return v; - v = key1->target_type - key2->target_type; + v = spaceship_cmp(key1->target_type, key2->target_type); if (v) return v; - v = key1->target_class - key2->target_class; + v = spaceship_cmp(key1->target_class, key2->target_class); return v; } @@ -493,15 +495,15 @@ static int role_trans_cmp(const void *k1, const void *k2) const struct role_trans_key *key1 = k1, *key2 = k2; int v; - v = key1->role - key2->role; + v = spaceship_cmp(key1->role, key2->role); if (v) return v; - v = key1->type - key2->type; + v = spaceship_cmp(key1->type, key2->type); if (v) return v; - return key1->tclass - key2->tclass; + return spaceship_cmp(key1->tclass, key2->tclass); } static const struct hashtab_key_params roletr_key_params = {