From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792437482; b=pXuWN4aVgZhmFDTJ+trRdqxvvlO3dKTKSjfltiJIgGDOyJG4N5Nw4t8DgndM9vPZNOSZ EP5B9zKep4lC0UzCd+n9vn5NrSj4QCbi9kJnqzFO7XQqj1L0/lnCrRRTAILelbGokAKmL ns/rzYqzGRvO/J30jtHtYqnkDLwNmMGLCQGs4UPQqnUKf0ypNwMTHoIwI4fBoyZzaMHKv MVDQ7mJLR0GVyUZzKVKT8iJe1cQWKZLtH9aN9/erh1a+4h3xT6De+hrRn/lCeVOvMWo84 qc4hB4NQRsOyqC+oMdWgrsL6+QfUK1Bqcwhhgw1On/kehs+n/phslOi0d5BkDbn4x1A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792437482; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=HOOxhWe0N25Vvh+QP+0h17bAVDCPz4LE/9nK0BEyyGI=; b=wUCEoPEHUJXBorB0dFWkIsPzjUDsIaZ6E/CK7p81nGY8uQlYODj0qgD1apvMlUeznS2j QLqEa0pDz6dGPBfjJWy+XRS3fd4flLy+U018u0nA5OGlAqNLWxmD064qY0IcZT1f8Vkcq MQ5hxa58VfL+MWtd+UojpqthPaz0iKwu8BIyTN37oZBGhWmgcqIo+1d6CFwqa9ZseLqbq TH3N0MjWAJkbVim/JfZqE26G/hIolgSPyeAdZh4jQTtx/ON+poV+PRiE5HUtDgFKRuZSP +DMZwMERtNEThSr6bdMBcXPW90pzLU8JxjIqv+cOxFpnC/V7g55XBj+RjyNwsNb75BA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=LCqqTU6G; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C56FB606A31C; Mon, 19 Oct 2026 19:18:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=LCqqTU6G Received: by smtp.kernel.org (Postfix) with ESMTPSA id 017551F000C4; Mon, 19 Oct 2026 19:18:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792437481; bh=HOOxhWe0N25Vvh+QP+0h17bAVDCPz4LE/9nK0BEyyGI=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=LCqqTU6G2extdImFhREVnfwGUIRAcaS40Wu2sPK7PcgEG5e/17rHq/cNlzXr4QMQx FrMxowqdRm8+rMs7BKMxRMrwTe2kBS1tcSQ4//GSa9/Ev99lJSPaxa2H82umuXHU+V 0LNWGZ3eyWrvIfl8/ouRHQvXwFusr+HR3i9kfqdaQ1UIxbQKMtfjKXf+RCVMIP+Zdy xXmRIKfh/SZOoW80+xblSo3OYO/ltnfjJ3s4fLLcJMrRCj29U3UbxQsh9rZZO+4rr3 3SAs8cz8k9PnP3tKfmRZdNp8ehtyRrkYRT+7xvQ6JRA+CxuqvIV0j3a7e1Jd/GdUaS c9q4L6xwBRPYA== Date: Mon, 19 Oct 2026 12:17:59 -0700 From: Eric Biggers To: Jarkko Sakkinen Cc: David Howells , keyrings@vger.kernel.org, stable@vger.kernel.org, Paul Moore , James Morris , "Serge E. Hallyn" , open list , "open list:SECURITY SUBSYSTEM" Subject: Re: [PATCH v2 2/6] KEYS: Reject @desclen values >= KEY_MAX_DESC_SIZE in key_alloc() Message-ID: <20261019191759.GB65095@quark> References: <20261019181732.449591-1-jarkko@kernel.org> <20261019181732.449591-3-jarkko@kernel.org> X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261019181732.449591-3-jarkko@kernel.org> On Mon, Oct 19, 2026 at 09:17:22PM +0300, Jarkko Sakkinen wrote: > @desclen in key_alloc() is saved to the 16-bit wide desc_len field in > struct keyring_index_key. > > Reject @desclen values at or above KEY_MAX_DESC_SIZE with -EINVAL in > order to account for the NUL terminator and prevent integer overflow. This should say something like: "in order to match the userspace limit and avoid u16 truncation". There are also similar truncations of desc_len to u16 in key_create_or_update() and keyring_search(). > +#define KEY_MAX_DESC_SIZE 4096 Could use a comment mentioning that it includes the trailing NUL. - Eric