From patchwork Thu Feb 8 08:44:20 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lee Jones X-Patchwork-Id: 13549444 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 CEF3973197; Thu, 8 Feb 2024 08:45:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707381935; cv=none; b=P5SIe56mslZgqf4RR5nwrJDU9Yk1J9q87rR60UE8q21T7MMvb5y4xU+TCseACIZnx+QIc8OcQYwFfoX+TNeDCljTXMMX4PZ4i26Ca1lP0E/+kisWZRrORX02sqxThLQsfUURFOl3zvRDO+cfvuPhSG1zKF7N1BGVRnG7VUHQZsI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707381935; c=relaxed/simple; bh=QcWkvLbuXqKsmCSILThA1RfLwMeDripObvnvLFWiq34=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fDe2rypoyWtpnB06izoJQSLDq47rc6o3uHT2waOB85hlw/BcTJUUZnfYbeUp3EsQTDq0EUcNO5rxyjbhb5E1slsTIchW3Sazk6TiYqp9A765vXVJLh0DLs7RkcMVnVY7uDeFdKCMumFBfiXUhV5RtL7qjQX2wiJkpj5Ilpu9JNs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=flkB5vKC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="flkB5vKC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0A257C433C7; Thu, 8 Feb 2024 08:45:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707381935; bh=QcWkvLbuXqKsmCSILThA1RfLwMeDripObvnvLFWiq34=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=flkB5vKCBQYz/TpY0INSUaOZjllm7VrkDUbKFVgCIc3ASXj/qazrW94Yryh3JnsNX NJlgNNRcRUnXProGsUi8C60pgUya/Fr+EbvRfWtqbhO2YHZE25gcmPGLdWv0WujarZ cWbsO1A+1oAk30b0gsn/JJRxxxx7v+Ya+QMQQeTauB49jBXRvaud7rZaPGDH6v1Sm9 BshS6lbql3Lky3xkzhJ3qkII+o16i592ZP1lJ90hMoELZdsv6nOxN6LrniXK5qTPYr QEA8Dul1ponHXK0/KmqqAqeurIbVE98UbjMLuIfEWXQG0CQZgxl22y8j+OgKOr8sY/ u8EUQhEi+CBGg== From: Lee Jones To: lee@kernel.org Cc: linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, Hannes Reinecke , "James E.J. Bottomley" , "Martin K. Petersen" , linux-scsi@vger.kernel.org Subject: [PATCH 08/10] scsi: aic7xxx: aicasm: Replace snprintf() with the safer scnprintf() variant Date: Thu, 8 Feb 2024 08:44:20 +0000 Message-ID: <20240208084512.3803250-9-lee@kernel.org> X-Mailer: git-send-email 2.43.0.594.gd9cf4e227d-goog In-Reply-To: <20240208084512.3803250-1-lee@kernel.org> References: <20240208084512.3803250-1-lee@kernel.org> Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 There is a general misunderstanding amongst engineers that {v}snprintf() returns the length of the data *actually* encoded into the destination array. However, as per the C99 standard {v}snprintf() really returns the length of the data that *would have been* written if there were enough space for it. This misunderstanding has led to buffer-overruns in the past. It's generally considered safer to use the {v}scnprintf() variants in their place (or even sprintf() in simple cases). So let's do that. Link: https://lwn.net/Articles/69419/ Link: https://github.com/KSPP/linux/issues/105 Signed-off-by: Lee Jones Reviewed-by: Kees Cook --- Cc: Hannes Reinecke Cc: "James E.J. Bottomley" Cc: "Martin K. Petersen" Cc: Lee Jones Cc: linux-scsi@vger.kernel.org --- drivers/scsi/aic7xxx/aicasm/aicasm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/aic7xxx/aicasm/aicasm.c b/drivers/scsi/aic7xxx/aicasm/aicasm.c index 8d995186e557a..bc758e78d3c06 100644 --- a/drivers/scsi/aic7xxx/aicasm/aicasm.c +++ b/drivers/scsi/aic7xxx/aicasm/aicasm.c @@ -331,7 +331,7 @@ back_patch() if (cur_instr->patch_label->type != LABEL) { char buf[255]; - snprintf(buf, sizeof(buf), + scnprintf(buf, sizeof(buf), "Undefined label %s", cur_instr->patch_label->name); stop(buf, EX_DATAERR);