From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-178.mta1.migadu.com (out-178.mta1.migadu.com [95.215.58.178]) (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 2D7A825DCF0 for ; Mon, 13 Oct 2025 11:41:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760355666; cv=none; b=lH3rh+5zsKMvrTpEAVg5UKKHBhHFS1iurN2lo+UoPeDnPI0qcwdcdUwwUvseR+aj6/2Bdmy2StrjC9KuT5wQmblNm3qnKHtavEx0IrG96G+CpVbKZc5fYTh6eSaGjtDT8okMr8VKkBqDS46PyC1Abuj/fAh9FnkY61H3MkQdHW0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760355666; c=relaxed/simple; bh=YIhRZUMEmVTbbTq0qn+Wub1X6vQ1RDEZasIjBykI58w=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=WfFr5/qEGq4mHx7MpvxzuCG3j7ESX2DSd1whOzjrO353J4yAik9bo7iHfxX3/vSz4lZQ9vOtTsyUKDYtWmM4Ry3MJt11zu4oU1nWUXn5CBftk2ytsspyL48O4V4E9strXbcDmYrXg+JrNGtV8Wiyl3R8FrWA41+XrKgRdvcyU9I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=Qc8+Kz2T; arc=none smtp.client-ip=95.215.58.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="Qc8+Kz2T" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1760355649; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=9Vu1Cpg8he0xK6peV8K87vsvIV7h3hjSS/e58iVfYGw=; b=Qc8+Kz2T30hBKGXDUI1IEyKZjPYMLuHrMVsW+fT91ZmxlTBt5XAQwDixGEB93hgAMNWgv3 Q5V5RqAJgV77UHBzBNCt1XukA6yChd9OWYdsWYUDds28caojAKkyg48ZKDeOowHwamd2ge LN2kcm+nPyldBiMBG8+Y6lzwbZaolEI= From: Thorsten Blum To: David Howells , Lukas Wunner , Ignat Korchagin , Herbert Xu , "David S. Miller" , Vivek Goyal Cc: Thorsten Blum , keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3] crypto: asymmetric_keys - prevent overflow in asymmetric_key_generate_id Date: Mon, 13 Oct 2025 13:40:10 +0200 Message-ID: <20251013114010.28983-2-thorsten.blum@linux.dev> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Use check_add_overflow() to guard against potential integer overflows when adding the binary blob lengths and the size of an asymmetric_key_id structure and return ERR_PTR(-EOVERFLOW) accordingly. This prevents a possible buffer overflow when copying data from potentially malicious X.509 certificate fields that can be arbitrarily large, such as ASN.1 INTEGER serial numbers, issuer names, etc. Fixes: 7901c1a8effb ("KEYS: Implement binary asymmetric key ID handling") Signed-off-by: Thorsten Blum --- Changes in v3: - Also use check_add_overflow() for adding the struct size itself as suggested by Lukas - Drop struct_size() - Update patch description - Drop patch 2/2 - Link to v2: https://lore.kernel.org/lkml/20251012203841.60230-1-thorsten.blum@linux.dev/ Changes in v2: - Use check_add_overflow() and error out as suggested by Lukas - Update patch description - Add Fixes: tag and @stable for backporting - Link to v1: https://lore.kernel.org/lkml/20251007185220.234611-2-thorsten.blum@linux.dev/ --- crypto/asymmetric_keys/asymmetric_type.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c index ba2d9d1ea235..348966ea2175 100644 --- a/crypto/asymmetric_keys/asymmetric_type.c +++ b/crypto/asymmetric_keys/asymmetric_type.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include #include @@ -141,12 +142,17 @@ struct asymmetric_key_id *asymmetric_key_generate_id(const void *val_1, size_t len_2) { struct asymmetric_key_id *kid; - - kid = kmalloc(sizeof(struct asymmetric_key_id) + len_1 + len_2, - GFP_KERNEL); + size_t kid_sz; + size_t len; + + if (check_add_overflow(len_1, len_2, &len)) + return ERR_PTR(-EOVERFLOW); + if (check_add_overflow(sizeof(struct asymmetric_key_id), len, &kid_sz)) + return ERR_PTR(-EOVERFLOW); + kid = kmalloc(kid_sz, GFP_KERNEL); if (!kid) return ERR_PTR(-ENOMEM); - kid->len = len_1 + len_2; + kid->len = len; memcpy(kid->data, val_1, len_1); memcpy(kid->data + len_1, val_2, len_2); return kid; -- 2.51.0