Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 45D74367B9F; Thu, 20 Aug 2026 15:12:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787238780; cv=none; b=nE9Z3XnMPY7tU/FHhhr4jisG+kNdgZBo0EVdardlme52P/nLmBEkhFnMu9qs8Zt/fxparBEcmLZzjLF+P4bShSPDz+kwkPz5UdyD76LtLmz7HJWGwXdUHe/ftGpc9qdkNgBuk3C8hW/QsMqj5RM2FpQOySNFMJ/TE/sAo2niV3Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787238780; c=relaxed/simple; bh=B9jwYqdtbe7YCXMAxztK1LjG86I1OFU9F34DyAKodjM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HZz/2VVqnkWSxPtvfimgtfGjPGj0DwxaKfHoa7WT6e/6mMg0MJOHmlNXymX+rG3YjgG66AhwAGp80xH6oj8up6J+ymEzPGIdDMO2p5u2jYh9A1t7kVcpb47kquTZMGET/8eZ4m301XFGCLdA6YE13kf6GaK4YrFVrveN/bQ7o5s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LXsk+HvI; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="LXsk+HvI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A1AE31F000E9; Thu, 20 Aug 2026 15:12:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787238779; bh=ukgt5ekK2xvmXf7NjMexoWa/2llBEL8E0N9jDmxvqg8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=LXsk+HvInL8oo6cgNN5nlb6ukL+HxZ/2TBuQenTwIzDfdtSZYccX3Xxo8NDM0cVUt tvfI25qeWYoFfWjF8O+RhGkQst7GiGJ0td/UFQ2GtSIQP2UpYLFtb1qLT8Z8BuVbsd 5gCVgQwUwwXi617+L/HUeSNqjENG8Hut/bYuT4KM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Bryam Vargas , Stephen Smalley , Paul Moore Subject: [PATCH 6.18 007/217] selinux: reject a class permission count below its inherited common Date: Thu, 20 Aug 2026 16:52:55 +0200 Message-ID: <20260820145237.787588676@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260820145237.531699751@linuxfoundation.org> References: <20260820145237.531699751@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bryam Vargas commit 9a82dcd98b6e6e11cfd162410967951f12152528 upstream. security_get_permissions() maps an inherited common's permissions into an array sized by the class's own permissions.nprim, but class_read() takes that nprim verbatim from the policy image and never checks that it covers the common. A class that inherits a common of N permissions while declaring a smaller nprim is accepted, and on load the common's permissions are written past the class-sized array -- an out-of-bounds heap write. Reject a class whose permission count is below its inherited common's. Well-formed policies, where the class count already includes the inherited permissions, are unaffected. Cc: stable@vger.kernel.org Fixes: 55fcf09b3fe4 ("selinux: add support for querying object classes and permissions from the running policy") Signed-off-by: Bryam Vargas Acked-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman --- security/selinux/ss/policydb.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -1385,6 +1385,18 @@ static int class_read(struct policydb *p cladatum->comkey); goto bad; } + + /* + * security_get_permissions() maps the common's permissions + * into an array sized by this class's nprim, so a class must + * declare at least as many as the common it inherits. + */ + if (cladatum->permissions.nprim < + cladatum->comdatum->permissions.nprim) { + pr_err("SELinux: class %s has fewer permissions than common %s\n", + key, cladatum->comkey); + goto bad; + } } for (i = 0; i < nel; i++) { rc = perm_read(p, &cladatum->permissions, fp);