From patchwork Thu Feb 8 08:44:17 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lee Jones X-Patchwork-Id: 13549441 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 BD9E76F50B; Thu, 8 Feb 2024 08:45:30 +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=1707381930; cv=none; b=pRNvSYdpR6WtHe0ixlMojdHwOLJw2ek08pdHY5Gh/THdpAHUK0RktIrMgFf4ETHlQvyCHYMf0eYDQwP6ccsLhYhAPHOVHcO47NPJcyVbhzRRdxCO/7xqPIvqELZ0TfzyOcYK1d/Z+m7/6g0mXEg1AsCfNK9zopYMVjv7taI6kRA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707381930; c=relaxed/simple; bh=POI6uCurjz7K0SS0gUH7C3Dj3W11IBfcHS/B+rMzmkI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MzKDprN1HdM+KjIMnES3wfAaXrhCWSlkBmRcPwwVZw9/u8IcUpH6K1vPXoVcp7QdC+67ffTUJJJoqHccse8M3njbSqeJCH8e+DF5U2RsRHSwnl5KNwOH7OQycsLSUV43WqbMp/tD/LGNY5ReMtcRSS2D43o0Hjd4mg/NbVmXItY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Oj59yN2b; 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="Oj59yN2b" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 35D6BC43390; Thu, 8 Feb 2024 08:45:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707381930; bh=POI6uCurjz7K0SS0gUH7C3Dj3W11IBfcHS/B+rMzmkI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Oj59yN2bU3sJBgizsn6x4fu41c/QIs6ntSTGN6Z6dvCS6XlPGrpVhwSHlXNhm9jYA BBwC+V2MHkoX+xdCMOcKeEIgSyivDMoGE33cZyG8h5dsmw80W5L7ddNrgWnq+JOGOY hVto3EU37cOv/sJvJH7tQRWIIqxk9tMHVc0myon3u/a8NBRPOaPeZVHf3dGTA/3YYl RzeI1rmPJ/BZHLFQx9+ctK99WAV7ebDzgMq9h7lQULRsUzX6IvJzq3SpsaZ8uOUMzL TkZe+CbIPCDJmesRHbtfmWSdsLeR2vbt0ClkeMbRGCnu0VDW4/w3fLJIgkg53EXybs pXeitHIQV0JkQ== From: Lee Jones To: lee@kernel.org Cc: linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, Adaptec OEM Raid Solutions , "James E.J. Bottomley" , "Martin K. Petersen" , "PMC-Sierra, Inc" , linux-scsi@vger.kernel.org Subject: [PATCH 05/10] scsi: aacraid: linit: Replace snprintf() with the safer scnprintf() variant Date: Thu, 8 Feb 2024 08:44:17 +0000 Message-ID: <20240208084512.3803250-6-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 --- Cc: Adaptec OEM Raid Solutions Cc: "James E.J. Bottomley" Cc: "Martin K. Petersen" Cc: "PMC-Sierra, Inc" Cc: linux-scsi@vger.kernel.org --- drivers/scsi/aacraid/linit.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/aacraid/linit.c b/drivers/scsi/aacraid/linit.c index 69526e2bd2e78..0e47d9c4cff23 100644 --- a/drivers/scsi/aacraid/linit.c +++ b/drivers/scsi/aacraid/linit.c @@ -583,7 +583,7 @@ static ssize_t aac_show_unique_id(struct device *dev, if (sdev_channel(sdev) == CONTAINER_CHANNEL) memcpy(sn, aac->fsa_dev[sdev_id(sdev)].identifier, sizeof(sn)); - return snprintf(buf, 16 * 2 + 2, + return scnprintf(buf, 16 * 2 + 2, "%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X\n", sn[0], sn[1], sn[2], sn[3], sn[4], sn[5], sn[6], sn[7], @@ -1302,13 +1302,13 @@ static ssize_t aac_show_serial_number(struct device *device, int len = 0; if (le32_to_cpu(dev->adapter_info.serial[0]) != 0xBAD0) - len = snprintf(buf, 16, "%06X\n", + len = scnprintf(buf, 16, "%06X\n", le32_to_cpu(dev->adapter_info.serial[0])); if (len && !memcmp(&dev->supplement_adapter_info.mfg_pcba_serial_no[ sizeof(dev->supplement_adapter_info.mfg_pcba_serial_no)-len], buf, len-1)) - len = snprintf(buf, 16, "%.*s\n", + len = scnprintf(buf, 16, "%.*s\n", (int)sizeof(dev->supplement_adapter_info.mfg_pcba_serial_no), dev->supplement_adapter_info.mfg_pcba_serial_no);